{ "model": { "rank": 2975, "code": "thing-q162455", "model_id": "vr.tr.gini-coefficient", "name": "Gini coefficient", "purpose": "Enable an AI agent to identify, interpret, compare and assess the permitted uses of a Gini coefficient by recording the distribution measured, calculation convention and evidential limitations.", "family": "Thing Registry", "category": "Cross-cutting context", "status": "research-draft", "kind": "thing", "plane": "XCT", "domain": "XCT.QLT", "industry": "", "version": "", "url": "/models/thing/q162455/", "tier": 2, "score": 93, "payload": { "layer": "wikidata", "aliases": [], "aliasCount": 0, "merged": 0, "knownIn": 93, "facets": null, "markers": [], "lexicalClass": "", "senseRank": null, "alsoRegisteredAs": null, "source": { "dataset": "wikidata", "item": "Q162455", "url": "https://www.wikidata.org/wiki/Q162455", "license": "CC0 1.0" } }, "research": { "vercy": "1.0-draft", "publication": { "status": "research-draft", "adjudicationStatus": "unreviewed", "publishableCanonical": false, "generatedAt": "2026-09-07T14:04:08Z", "providers": [ "Codex", "Grok" ], "missingProviders": [], "pass": 2, "cost": { "grok": { "usd": 0.00862954, "turns": 1, "seconds": 136.3, "error": null }, "codex": { "seconds": 79.9, "error": "Reading additional input from stdin...\nOpenAI Codex v0.153.3\n--------\nworkdir: R:\\02_PROJECTS\\02_Meta_Models_Platforms\\Ver.cy\\current\\thing-registry-backlog\nmodel: gpt-6-astra\nprovider: openai\napproval: never\nsandbox: read-only\nreasoning effort: none\nreasoning summaries: none\nsession id: 01a07c29-feaf-7e10-a703-38b4b06feeef\n--------\nuser\nYou are drafting a Vercy meta-model for one registered thing. Answer as JSON only, no prose around it.\n\nThing: Gini coefficient\nRegistry id: vr.tr.gini-coefficient\nPlane / domain: INF / INF.MED\nRegistry definition: (none recorded)\nNames folded into this entry:" } } }, "metaModel": { "id": "THING-Q162455", "registryId": "vr.tr.gini-coefficient", "name": "Gini coefficient", "version": "0.1.0-research.1", "entryKind": "thing", "family": "Thing Registry", "domain": [ "INF.MED" ], "status": "research-draft" }, "canonicalUrl": "https://ver.cy/models/thing/q162455/", "model": { "registry_id": "vr.tr.gini-coefficient", "name": "Gini coefficient", "purpose": "Enable an AI agent to identify, interpret, compare and assess the permitted uses of a Gini coefficient by recording the distribution measured, calculation convention and evidential limitations.", "definition": "The Gini coefficient is a relative, scale-invariant inequality index equal to half the mean absolute pairwise difference of a distribution divided by its mean (equivalently, twice the area between the Lorenz curve and the egalitarian diagonal); for a non-negative variable it is 0 under complete equality and approaches 1 as one unit holds the entire total.", "scope_statement": "This model owns the identity, interpretation and fitness for use of a Gini coefficient estimate, including its relationship to a specified distribution, population, reference period and estimation procedure.", "in_scope": [ "The quantity whose inequality or concentration is measured and the units across which it is distributed", "The reported coefficient, numerical scale, formula and normalization convention", "Population coverage, weighting, data treatment and estimation uncertainty", "Conditions for comparing coefficients across populations, periods or methods", "Interpretive limits and decisions about whether an estimate can support a proposed claim" ], "out_of_scope": [ "The underlying household survey, administrative dataset or sampling system as independently managed objects", "Complete income, wealth, consumption or other accounting frameworks", "Poverty, welfare and social justice assessments beyond the inequality information supplied by the coefficient", "Alternative inequality measures such as Theil indices, Atkinson indices and percentile ratios", "Decision-tree Gini impurity and predictive discrimination metrics called Gini", "Policies intended to change a distribution and evaluations of their causal effects" ], "distinguishing_features": [ "Represents inequality or concentration across a distribution of quantities; it does not identify the distribution's average level, total size or poverty rate.", "For a nonnegative distribution with positive mean, the conventional coefficient is associated with the area between the Lorenz curve and the equality line and can be expressed using normalized pairwise absolute differences.", "A reported value requires a declared scale: a coefficient on a 0-1 scale and an index on a 0-100 scale can express the same estimate.", "Decision-tree Gini impurity measures category mixing, while predictive Gini commonly derives from discrimination performance; sharing the name does not make either the distributional coefficient modeled here.", "Equal Gini coefficients do not establish identical distributions or Lorenz curves, and a Gini ranking alone does not establish Lorenz dominance." ], "characteristics": [ { "name": "Reported Gini value", "kind": "measurement", "unit_or_values": "Dimensionless; record the reported number and whether its scale is 0-1, 0-100 or another declared convention", "why_it_matters": "Prevents scale errors and preserves the published estimate without assuming that every input distribution satisfies conventional bounds." }, { "name": "Distributed quantity", "kind": "category", "unit_or_values": "Income, wealth, consumption, land holdings or another explicitly defined quantity", "why_it_matters": "The same numerical coefficient has different substantive meaning when applied to different quantities." }, { "name": "Resource accounting basis", "kind": "category", "unit_or_values": "For example, gross or disposable income; individual, household, per-capita or equivalised resources; applicable reference period", "why_it_matters": "Accounting and allocation choices can change measured inequality before any population change occurs." }, { "name": "Represented population and counting unit", "kind": "relation", "unit_or_values": "Links to the target population, geographic coverage, eligibility rules and units receiving statistical weight", "why_it_matters": "Distinguishes inequality among households from inequality among people assigned household resources." }, { "name": "Estimator and normalization", "kind": "category", "unit_or_values": "Declared formula, weighting procedure, grouped-data approximation and any finite-sample correction", "why_it_matters": "Different conventions can yield different values and attainable upper bounds for the same observations." }, { "name": "Input-domain condition", "kind": "state", "unit_or_values": "Nonnegative with positive mean; all zero; negative observations present; zero or negative mean; unknown", "why_it_matters": "Determines whether conventional bounds and interpretations apply and whether the stated formula is defined." }, { "name": "Statistical uncertainty", "kind": "measurement", "unit_or_values": "Standard error or interval on a declared Gini scale, with confidence level and estimation method; unavailable when not estimated", "why_it_matters": "Supports assessment of whether observed differences exceed sampling uncertainty." }, { "name": "Comparability assessment", "kind": "state", "unit_or_values": "Comparable for a stated purpose; comparable after documented adjustment; not comparable; unresolved", "why_it_matters": "Prevents differences in coverage, accounting or calculation from being mistaken for changes in inequality." } ], "affordances": [ "Identify whether a reported Gini refers to distributional inequality and attach its population, resource definition and period.", "Convert between declared numerical scales while preserving the source value and calculation convention.", "Calculate or reproduce a coefficient from suitable data using an explicit estimator and documented input treatment.", "Assess whether a value is mathematically interpretable under its input conditions and normalization.", "Compare estimates after checking resource definitions, populations, methods and uncertainty.", "Qualify or reject claims that infer poverty, welfare, distributional identity or causal effects from the coefficient alone." ] }, "sources": [ { "id": "gini-1912", "title": "Variabilità e mutabilità", "url": "", "what_it_supports": "Original definition of the mean-difference / concentration measure later called the Gini coefficient." }, { "id": "atkinson-1970", "title": "On the measurement of inequality", "url": "", "what_it_supports": "Places Gini among Lorenz-consistent inequality indices and contrasts it with the Atkinson family." }, { "id": "canberra-2011", "title": "Canberra Group Handbook on Household Income Statistics, 2nd edition", "url": "", "what_it_supports": "International conventions on income concepts (market, gross, disposable) that determine which Gini is being reported." }, { "id": "wdi-sipovgini", "title": "World Development Indicators: Gini index (World Bank estimate), SI.POV.GINI", "url": "https://data.worldbank.org/indicator/SI.POV.GINI", "what_it_supports": "The dominant country-year series, the 0-100 reporting scale, and typical cross-country ranges for income Gini.", "url_status": "live" }, { "id": "oecd-idd", "title": "OECD Income Distribution Database (IDD)", "url": "", "what_it_supports": "The market versus disposable split, equivalisation practice, and OECD-area levels used in policy comparison." }, { "id": "cowell-2011", "title": "Measuring Inequality, 3rd edition", "url": "", "what_it_supports": "Formal properties (Pigou-Dalton, decomposability limits, relation to the Lorenz curve) and neighbouring indices." } ], "structure": { "bundles": [ { "id": "distributional-target", "name": "Distributional target", "description": "Identifies what is distributed, among whom and over which reference period.", "rationale": "A Gini value cannot be interpreted until the resource and recipient population are specified.", "layers": [ { "id": "resource-definition", "name": "Resource definition", "description": "Captures the substantive quantity and accounting choices underlying the distribution.", "findings": [ { "id": "resource-and-accounting-basis", "name": "Resource and accounting basis", "description": "Establishes whether the coefficient measures income, wealth, consumption or another quantity and how that quantity is constructed.", "questions": [ { "text": "What quantity is distributed, and which components, taxes, transfers, liabilities or in-kind resources are included where applicable?", "kind": "definition", "id": "resource-and-accounting-basis-q01" }, { "text": "Does the quantity represent a stock at a date or a flow over a period, and what date or period applies?", "kind": "boundary", "id": "resource-and-accounting-basis-q02" } ] } ] }, { "id": "recipients-and-coverage", "name": "Recipients and coverage", "description": "Separates the recorded observation unit from the population represented by the inequality estimate.", "findings": [ { "id": "population-and-resource-allocation", "name": "Population and resource allocation", "description": "Records who is counted and how resources are assigned to those units.", "questions": [ { "text": "Which geographic and eligibility boundaries define the population, and which groups are excluded?", "kind": "boundary", "id": "population-and-resource-allocation-q01" }, { "text": "Is inequality calculated across people, households or other units, and are household resources assigned using per-capita division or an equivalence scale?", "kind": "definition", "id": "population-and-resource-allocation-q02" } ] } ] } ] }, { "id": "coefficient-convention", "name": "Coefficient convention", "description": "Identifies the mathematical statistic, reported scale and normalization used.", "rationale": "The Gini name and number alone do not establish which statistic or finite-population convention was applied.", "layers": [ { "id": "statistic-identity", "name": "Statistic identity", "description": "Distinguishes the distributional coefficient from other statistics sharing its name.", "findings": [ { "id": "formula-and-scale", "name": "Formula and scale", "description": "Connects the reported number to an explicit distributional Gini definition.", "questions": [ { "text": "Which formula defines this estimate, and does it measure distributional inequality rather than classification impurity or predictive discrimination?", "kind": "definition", "id": "formula-and-scale-q01" }, { "text": "What value was reported, on which numerical scale and with what rounding precision?", "kind": "measurement", "id": "formula-and-scale-q02" } ] } ] }, { "id": "normalization-and-bounds", "name": "Normalization and bounds", "description": "Captures corrections and the bounds justified by the chosen estimator and input domain.", "findings": [ { "id": "attainable-range", "name": "Attainable range", "description": "Establishes how sample size, weighting and normalization affect the coefficient's interpretation.", "questions": [ { "text": "Is a finite-sample correction or other rescaling applied, and how is it defined for the weighting scheme used?", "kind": "definition", "id": "attainable-range-q01" }, { "text": "What minimum and maximum are attainable under this formula, population size, weight structure and input domain?", "kind": "measurement", "id": "attainable-range-q02" } ] } ] } ] }, { "id": "estimation-and-data-treatment", "name": "Estimation and data treatment", "description": "Records how evidence becomes a coefficient and how problematic observations are handled.", "rationale": "Grouping, weights and treatment of zero, negative or extreme values can materially change a Gini estimate.", "layers": [ { "id": "evidence-and-calculation", "name": "Evidence and calculation", "description": "Identifies the input evidence and the calculation path used to produce the estimate.", "findings": [ { "id": "input-resolution-and-weights", "name": "Input resolution and weights", "description": "Distinguishes calculations from unit records, grouped shares and modeled distributions.", "questions": [ { "text": "Which dataset, release or publication supplies the estimate, and is it calculated from unit records, grouped distribution shares or a fitted distribution?", "kind": "provenance", "id": "input-resolution-and-weights-q01" }, { "text": "Which weights, interpolation assumptions and calculation implementation are used, and are they documented sufficiently to reproduce the value?", "kind": "measurement", "id": "input-resolution-and-weights-q02" } ] } ] }, { "id": "exceptional-inputs", "name": "Exceptional inputs", "description": "Captures departures from the conventional nonnegative, positive-mean setting and modifications to the distribution.", "findings": [ { "id": "zeros-negatives-and-tail-treatment", "name": "Zeros, negatives and tail treatment", "description": "Records input conditions and transformations that affect mathematical validity or the measured target.", "questions": [ { "text": "Are zero or negative values present, what is the sign of the mean, and how does the estimator define or decline to define a result in those conditions?", "kind": "boundary", "id": "zeros-negatives-and-tail-treatment-q01" }, { "text": "Were observations dropped, imputed, top-coded, winsorised or shifted, and what justification and effect on the coefficient are documented?", "kind": "provenance", "id": "zeros-negatives-and-tail-treatment-q02" } ] } ] } ] }, { "id": "uncertainty-and-comparison", "name": "Uncertainty and comparison", "description": "Assesses the strength of an estimate and the legitimacy of comparisons made with it.", "rationale": "An apparent Gini difference may reflect estimation error or incompatible measurement choices.", "layers": [ { "id": "estimate-reliability", "name": "Estimate reliability", "description": "Separates statistical uncertainty from sensitivity to coverage and processing assumptions.", "findings": [ { "id": "sampling-and-method-sensitivity", "name": "Sampling and method sensitivity", "description": "Records uncertainty information without treating a sampling interval as a complete account of error.", "questions": [ { "text": "What standard error or confidence interval is available, and does its method account for the sample design?", "kind": "measurement", "id": "sampling-and-method-sensitivity-q01" }, { "text": "What evidence shows sensitivity to missing high-value observations, nonresponse, imputation or grouped-data assumptions?", "kind": "measurement", "id": "sampling-and-method-sensitivity-q02" } ] } ] }, { "id": "comparison-eligibility", "name": "Comparison eligibility", "description": "Establishes whether two estimates can support a specified temporal or cross-population comparison.", "findings": [ { "id": "harmonization-and-series-breaks", "name": "Harmonization and series breaks", "description": "Identifies consequential differences in definitions, coverage and estimation methods.", "questions": [ { "text": "Do the estimates use compatible resource definitions, allocation rules, population coverage, reference periods, scales and estimator conventions?", "kind": "boundary", "id": "harmonization-and-series-breaks-q01" }, { "text": "Should the proposed comparison proceed, require harmonization or remain unresolved given series breaks and uncertainty in the difference?", "kind": "action", "id": "harmonization-and-series-breaks-q02" } ] } ] } ] }, { "id": "interpretation-and-permitted-inference", "name": "Interpretation and permitted inference", "description": "Defines what the coefficient supports and what requires additional distributional evidence.", "rationale": "A single inequality summary loses information needed for many rankings, explanations and decisions.", "layers": [ { "id": "distributional-information-limits", "name": "Distributional information limits", "description": "Relates the coefficient to Lorenz curves and records the limits of scalar rankings.", "findings": [ { "id": "lorenz-evidence-and-ranking", "name": "Lorenz evidence and ranking", "description": "Distinguishes a numerical Gini ordering from stronger statements about distributions.", "questions": [ { "text": "Are the associated Lorenz curves or distribution shares available, and do the curves cross over the population range?", "kind": "measurement", "id": "lorenz-evidence-and-ranking-q01" }, { "text": "Does the proposed claim require only a Gini ranking, or does it require evidence of Lorenz dominance or changes in specific parts of the distribution?", "kind": "boundary", "id": "lorenz-evidence-and-ranking-q02" } ] } ] }, { "id": "decision-use", "name": "Decision use", "description": "Connects the estimate to a stated analytical action without extending its meaning beyond the evidence.", "findings": [ { "id": "claim-support-and-complementary-evidence", "name": "Claim support and complementary evidence", "description": "Determines which claims can use the coefficient and which require separate measures or causal analysis.", "questions": [ { "text": "What proposed decision or statement will use this estimate, and is there a documented rule for interpreting its value or change?", "kind": "action", "id": "claim-support-and-complementary-evidence-q01" }, { "text": "Which additional evidence is required before making claims about poverty, average living standards, subgroup contributions or the causal effect of a policy?", "kind": "action", "id": "claim-support-and-complementary-evidence-q02" } ] } ] } ] }, { "id": "evidence-and-external-alignment", "name": "Evidence and external alignment", "description": "What the world already says about this thing, gathered so the model can be checked against it.", "rationale": "A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.", "layers": [ { "id": "reported-evidence", "name": "Reported evidence", "description": "Findings from the breadth pass, kept separate from the structural claims.", "findings": [ { "id": "evidence-kinds", "name": "Kinds and varieties", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ "Market-income Gini (factor or pre-tax, pre-transfer income)", "Gross-income Gini (after transfers, before direct taxes)", "Disposable-income Gini (after taxes and transfers; the usual international headline)", "Wealth or net-worth Gini", "Consumption or expenditure Gini (common where income is poorly observed)", "Household-equivalised versus per-capita or individual Gini", "Generalized Gini / S-Gini (weighted by an inequality-aversion parameter)", "Spatial or concentration Gini (geographic or market shares rather than persons)" ], "questions": [ { "id": "evidence-kinds-q01", "text": "Which of these kinds and varieties hold for the sense of Gini coefficient this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-identifiers", "name": "Identifiers and schemes", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ { "scheme": "Wikidata", "value_or_pattern": "Q162455", "note": "Item for the Gini coefficient as an inequality statistic." }, { "scheme": "World Bank WDI indicator", "value_or_pattern": "SI.POV.GINI", "note": "Gini index (World Bank estimate), published on a 0-100 scale." }, { "scheme": "Eurostat dataset", "value_or_pattern": "ilc_di12", "note": "Gini coefficient of equivalised disposable income from EU-SILC." }, { "scheme": "OECD IDD series", "value_or_pattern": "Gini (disposable income, post taxes and transfers) and Gini (market income, before taxes and transfers)", "note": "Named series in the OECD Income Distribution Database, not a compact alphanumeric code." } ], "questions": [ { "id": "evidence-identifiers-q01", "text": "Which of these identifiers and schemes hold for the sense of Gini coefficient this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-standards-and-regulation", "name": "Standards and regulation", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ "Canberra Group Handbook on Household Income Statistics, 2nd ed. (UNECE / Canberra Group) - income concepts underlying most official Ginis.", "OECD Income Distribution Database methodology (OECD) - market/gross/disposable split, household equivalisation, and comparability rules for member countries.", "EU-SILC legal framework and Gini of equivalised disposable income (Eurostat / European Commission) - the EU structural indicator, using the modified OECD equivalence scale.", "Poverty and Inequality Platform (PIP) estimation methods (World Bank) - how survey microdata are turned into the SI.POV.GINI country series." ], "questions": [ { "id": "evidence-standards-and-regulation-q01", "text": "Which of these standards and regulation hold for the sense of Gini coefficient this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-real-world-use", "name": "Real-world use", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ "National statistical offices and the World Bank publish a country Gini as the headline inequality number in WDI and poverty assessments.", "OECD and EU social reporting compare disposable-income Gini across member states; finance ministries and tax-benefit models (e.g. EUROMOD) report the fall from market to disposable Gini as a fiscal-redistribution statistic.", "Household surveys in many low- and middle-income countries report a consumption Gini because income is seasonal or informal.", "Wealth Gini appears in central-bank and OECD wealth accounts, typically much higher than income Gini.", "Outside income statistics the same formula is used for land-holding concentration, health-outcome or health-expenditure inequality, and market-share concentration." ], "questions": [ { "id": "evidence-real-world-use-q01", "text": "Which of these real-world use hold for the sense of Gini coefficient this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-measurements", "name": "Typical measurements", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ { "quantity": "Gini coefficient (unit interval)", "typical_range": "0 (equality) to 1 (maximum inequality); national disposable-income values commonly about 0.24-0.63", "unit": "dimensionless (0-1)" }, { "quantity": "Gini index (World Bank / many NSOs)", "typical_range": "about 24-63 for contemporary national disposable or consumption income; global extremes occasionally outside that band", "unit": "index points on a 0-100 scale" }, { "quantity": "Wealth or net-worth Gini", "typical_range": "commonly about 0.55-0.90 in national household-wealth studies, well above the corresponding income Gini", "unit": "dimensionless (0-1)" }, { "quantity": "Redistributive gap (market Gini minus disposable Gini)", "typical_range": "often about 0.10-0.25 in high-tax OECD welfare states; much smaller where taxes and cash transfers are limited", "unit": "Gini points (0-1 scale)" } ], "questions": [ { "id": "evidence-measurements-q01", "text": "Which of these typical measurements hold for the sense of Gini coefficient this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-failure-modes-and-hazards", "name": "Failure modes and hazards", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ "Same Gini, different Lorenz curves: the scalar does not identify the shape of inequality (middle versus tails).", "Survey under-coverage and top-coding of high incomes bias the estimate downward; register or tax-data adjustments can move the number substantially.", "Negative incomes or wealth can push a computed Gini outside [0, 1] or make the mean-normalised index ill-behaved.", "Not additively decomposable by subgroup (unlike Theil / GE): between-group plus within-group Ginis leave a residual, so 'inequality due to X' claims are easy to overstate.", "Cross-country ranking collapses if income concept, equivalence scale, household versus individual unit, or consumption versus income is mixed.", "Finite-sample Gini is downward-biased in small n; naive sample formulae are not interchangeable with population formulae.", "Relative to Atkinson indices with high inequality aversion, Gini is less sensitive to the extreme poor and rich and can miss tail-driven welfare changes.", "Political use as a complete welfare ranking: Gini is not a social-welfare function and does not by itself say whether a rise is 'worse'." ], "questions": [ { "id": "evidence-failure-modes-and-hazards-q01", "text": "Which of these failure modes and hazards hold for the sense of Gini coefficient this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-regional-variation", "name": "Regional variation", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ "Reporting scale: World Bank and many NSOs use 0-100 ('Gini index'); academic and some European series use 0-1.", "EU practice is equivalised disposable income on the modified OECD scale from EU-SILC; the United States long published money-income Gini from the CPS, while CBO series that include taxes and transfers sit closer to the OECD concept.", "Latin America is often described with relatively high income Ginis; Nordic countries with register-based incomes sit at the low end of the OECD range.", "Many African and South Asian official series are consumption Ginis, not income Ginis, and are not interchangeable with OECD disposable-income figures.", "China's national Gini has historically depended on whether urban and rural surveys are pooled and how migrant households are sampled." ], "questions": [ { "id": "evidence-regional-variation-q01", "text": "Which of these regional variation hold for the sense of Gini coefficient this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-neighbours", "name": "Neighbouring kinds and how to tell them apart", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ { "name": "Lorenz curve", "difference": "The Lorenz curve is the full rank-share function; Gini is one scalar functional of it (twice the area to the diagonal). Identical Ginis can hide crossing Lorenz curves." }, { "name": "Atkinson index", "difference": "Atkinson is a social-welfare index with an explicit inequality-aversion parameter ε and is more tail-sensitive at high ε; Gini has no ε and a fixed rank-weighted form." }, { "name": "Theil index / generalised entropy GE(1)", "difference": "Theil is additively decomposable into between- and within-group terms with no residual; Gini is not." }, { "name": "Palma ratio", "difference": "Palma is the income share of the top 10% divided by that of the bottom 40%; it ignores the middle 50% by construction, whereas Gini uses the whole distribution." }, { "name": "Hoover / Pietra / Robin Hood index", "difference": "That index is the maximum vertical gap between the Lorenz curve and the diagonal (the share that would need to be transferred to equalise); Gini integrates the gap over the whole curve." }, { "name": "Percentile ratios (P90/P10, P90/P50)", "difference": "Ratios use two order statistics only; Gini uses all pairwise gaps. A change confined between two percentiles can move Gini and leave a given ratio unchanged, and conversely." }, { "name": "Coefficient of variation", "difference": "CV is the standard deviation over the mean (second-moment / GE(2) related); Gini is based on the L1 mean difference. CV is more sensitive to the upper tail." }, { "name": "Gini impurity (CART / classification)", "difference": "Gini impurity is 1 − Σ p_k², a node-heterogeneity score in decision trees. It shares a quadratic form with some Gini algebra but is not an inequality index of a cardinal distribution." } ], "questions": [ { "id": "evidence-neighbours-q01", "text": "Which of these neighbouring kinds and how to tell them apart hold for the sense of Gini coefficient this model covers, and on what evidence?", "kind": "provenance" } ] } ] } ] } ] }, "openQuestions": [ "Does the registry intend this entry to cover distributional Gini coefficients across all quantities, or specifically socioeconomic inequality?", "Does an existing Vercy world model already own the distributional Gini concept, requiring this registry entry to link to it?", "Which estimator and finite-sample normalization conventions should the model explicitly recognize, particularly for unequal weights?", "How should estimates involving negative observations or nonpositive means be classified, and which source-backed interpretations should be accepted?", "Which authoritative methodological sources should establish comparison requirements for income, wealth and consumption estimates?" ], "statistics": { "bundles": 6, "layers": 11, "findings": 18, "questions": 28 } }, "draft": { "generator": "vr.draft.v3", "status": "draft-generated", "researched": false, "archetype": "abstract concept", "method": "Written from the archetype playbook - what this kind of thing needs beyond identity and provenance - and from the structure that recurred across 6,333 models already researched by two engines. Applied to this entry by rule. No source was read for this thing and no claim here is researched. This entry carries no facets of its own, so they were inferred from its domain - a guess about a whole domain applied to one thing.", "facetsInferred": true, "nextPass": "A researcher replaces this draft with a sourced specification. Treat every sentence below as a proposal to argue with.", "purpose": "Give an agent a durable, checkable way to recognise a Gini coefficient, record what state it is in, and decide what may be done with it.", "whatItIs": "Enable an AI agent to identify, interpret, compare and assess the permitted uses of a Gini coefficient by recording the distribution measured, calculation convention and evidential limitations.", "characteristics": { "substance": "abstract", "origin": "conceptual", "agency": "inert" }, "whatYouCanDoWithIt": [ "observed and measured" ], "distinguishingFeatures": [ "Described in 93 Wikipedia languages, which is a measure of how widely the thing is known, not of how important it is." ], "openQuestionsForResearch": [ "Which of the bundles below does a real task actually need, and which are ceremony?", "What does this thing have that the facets do not capture at all?", "Which neighbouring kind is most often confused with a Gini coefficient, and on what evidence are they told apart?" ], "whatItIsMadeOf": "an abstraction with no physical instance", "physicalCharacter": [ "Does nothing on its own; everything it does, something else did to it.", "These come from the domain this entry sits in rather than from the entry itself, so treat them as a first guess about the whole domain applied to one thing." ], "whatCanBeDoneWithIt": [ "observe it, measure it, record its state" ], "howItIsRecognised": [ "Nothing to see. What is recognised is an instance of it, and which instances count is exactly what is argued about." ], "relatedModels": [], "standing": "Described in 93 Wikipedia languages, which measures how widely it is written about rather than how important or how common it is.", "structure": { "bundles": [ { "id": "identity-and-classification", "name": "Identity, naming and classification", "description": "How an agent tells one Gini coefficient from another, and a Gini coefficient from things that resemble it.", "rationale": "Recognition comes before every other claim. Without stable identity nothing else in the model can be trusted to be about the same thing twice.", "layers": [ { "id": "naming-and-identifiers", "name": "Names and identifiers", "description": "The names this thing goes by and the identifiers that survive translation and time.", "findings": [ { "id": "preferred-name-and-aliases", "name": "Preferred name, aliases and local names", "description": "Which name to use, which names mean the same thing, and which merely sound similar.", "questions": [ { "id": "preferred-name-and-aliases-q01", "text": "What identifies and describes the name of a Gini coefficient, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "preferred-name-and-aliases-q02", "text": "Who or what asserted this about the name of a Gini coefficient, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "preferred-name-and-aliases-q03", "text": "What may an agent decide or do once the name of a Gini coefficient is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] }, { "id": "stable-identifiers", "name": "Stable identifiers and external keys", "description": "Identifiers that keep pointing at this kind of thing across systems and languages.", "questions": [ { "id": "stable-identifiers-q01", "text": "What identifies and describes an identifier for a Gini coefficient, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "stable-identifiers-q02", "text": "Who or what asserted this about an identifier for a Gini coefficient, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "stable-identifiers-q03", "text": "What may an agent decide or do once an identifier for a Gini coefficient is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] }, { "id": "classification-and-granularity", "name": "Classification and granularity", "description": "Where a Gini coefficient sits among kinds, and how finely a task needs to cut it.", "findings": [ { "id": "kind-and-parents", "name": "Kind, parents and neighbouring kinds", "description": "The classes this thing belongs to and the ones it is next to.", "questions": [ { "id": "kind-and-parents-q01", "text": "What identifies and describes the kind of a Gini coefficient, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "kind-and-parents-q02", "text": "Who or what asserted this about the kind of a Gini coefficient, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "kind-and-parents-q03", "text": "What may an agent decide or do once the kind of a Gini coefficient is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] }, { "id": "distinguishing-features", "name": "Distinguishing features", "description": "What separates a Gini coefficient from the things most often confused with it.", "questions": [ { "id": "distinguishing-features-q01", "text": "What identifies and describes what distinguishes a Gini coefficient, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "distinguishing-features-q02", "text": "Who or what asserted this about what distinguishes a Gini coefficient, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "distinguishing-features-q03", "text": "What may an agent decide or do once what distinguishes a Gini coefficient is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] } ] }, { "id": "state-and-lifecycle", "name": "State and lifecycle", "description": "The states a Gini coefficient passes through and the events that move it between them.", "rationale": "Most decisions about a thing depend on what state it is in now, which is a claim with a time on it, not a property.", "layers": [ { "id": "lifecycle-stages", "name": "Lifecycle stages", "description": "From coming into existence to ceasing to be one of these.", "findings": [ { "id": "stages-and-transitions", "name": "Stages and transitions", "description": "The stages worth naming and what moves a Gini coefficient between them.", "questions": [ { "id": "stages-and-transitions-q01", "text": "What identifies and describes the lifecycle of a Gini coefficient, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "stages-and-transitions-q02", "text": "Who or what asserted this about the lifecycle of a Gini coefficient, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "stages-and-transitions-q03", "text": "What may an agent decide or do once the lifecycle of a Gini coefficient is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] }, { "id": "observations-and-status", "name": "Observations and current status", "description": "What is observed about a Gini coefficient, how often and by whom.", "findings": [ { "id": "observation-record", "name": "Observation record", "description": "How an observation of a Gini coefficient is recorded so that it can be superseded rather than overwritten.", "questions": [ { "id": "observation-record-q01", "text": "What identifies and describes an observation of a Gini coefficient, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "observation-record-q02", "text": "Who or what asserted this about an observation of a Gini coefficient, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "observation-record-q03", "text": "What may an agent decide or do once an observation of a Gini coefficient is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] } ] }, { "id": "definitions-in-contest", "name": "Definitions and who holds them", "description": "What Gini coefficient is taken to mean, and by whom.", "rationale": "When a field disagrees about a concept, the disagreement is the content. A model that picks one definition silently destroys the information.", "layers": [ { "id": "competing-definitions", "name": "Competing definitions", "description": "The main readings and the traditions behind them.", "findings": [ { "id": "definition-map", "name": "Definitions and their holders", "description": "Each definition with the school or body that holds it.", "questions": [ { "id": "definition-map-q01", "text": "Which definitions of Gini coefficient are in use, and which tradition or body holds each?", "kind": "definition" }, { "id": "definition-map-q02", "text": "What turns on the difference between them in practice?", "kind": "boundary" } ] } ] }, { "id": "operationalisation", "name": "Operationalisation", "description": "How it is measured or applied when it has to be.", "findings": [ { "id": "operational-record", "name": "Measures and proxies", "description": "Instruments and indicators used to stand in for it.", "questions": [ { "id": "operational-record-q01", "text": "How is Gini coefficient operationalised or measured in practice, and by what instrument?", "kind": "measurement" }, { "id": "operational-record-q02", "text": "What does that operationalisation leave out, and when does that matter?", "kind": "boundary" } ] } ] } ] }, { "id": "instances-and-use", "name": "Instances, use and consequence", "description": "What counts as an instance of Gini coefficient and what follows from calling something that.", "rationale": "Applying a concept is an act with consequences, so a model must say what the label licenses and what it does not.", "layers": [ { "id": "instances", "name": "What counts as an instance", "description": "Clear cases, borderline cases and non-cases.", "findings": [ { "id": "instance-tests", "name": "Tests for an instance", "description": "What would settle whether something falls under it.", "questions": [ { "id": "instance-tests-q01", "text": "What would settle whether something is an instance of Gini coefficient?", "kind": "boundary" }, { "id": "instance-tests-q02", "text": "Which borderline cases are argued about, and on what grounds?", "kind": "definition" } ] } ] }, { "id": "consequence", "name": "Consequence of application", "description": "Rights, duties or decisions that follow from the label.", "findings": [ { "id": "consequence-record", "name": "What the label licenses", "description": "What an agent may do once something is classified this way.", "questions": [ { "id": "consequence-record-q01", "text": "What follows practically once something is treated as Gini coefficient?", "kind": "action" }, { "id": "consequence-record-q02", "text": "What must an agent not infer from the label alone?", "kind": "action" } ] } ] } ] }, { "id": "provenance-and-evidence", "name": "Provenance, evidence and time", "description": "Where every claim about a Gini coefficient came from and when it held.", "rationale": "A claim without a source and a time cannot be superseded, only overwritten, and an agent that overwrites loses the ability to explain itself.", "layers": [ { "id": "source-and-authority", "name": "Source and authority", "description": "Who said it, on what evidence, and how strongly.", "findings": [ { "id": "claim-provenance", "name": "Claim provenance and confidence", "description": "The authority behind each claim about a Gini coefficient and how confident it is.", "questions": [ { "id": "claim-provenance-q01", "text": "What identifies and describes a claim about a Gini coefficient, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "claim-provenance-q02", "text": "Who or what asserted this about a claim about a Gini coefficient, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "claim-provenance-q03", "text": "What may an agent decide or do once a claim about a Gini coefficient is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] }, { "id": "time-and-versions", "name": "Time, versions and supersession", "description": "When a claim was true, when it was learnt, and what replaced it.", "findings": [ { "id": "validity-and-supersession", "name": "Validity period and supersession", "description": "How an old claim about a Gini coefficient is retired without being erased.", "questions": [ { "id": "validity-and-supersession-q01", "text": "What identifies and describes the validity of a claim about a Gini coefficient, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "validity-and-supersession-q02", "text": "Who or what asserted this about the validity of a claim about a Gini coefficient, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "validity-and-supersession-q03", "text": "What may an agent decide or do once the validity of a claim about a Gini coefficient is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] } ] } ] }, "statistics": { "bundles": 5, "layers": 10, "findings": 12, "questions": 32 } } } }