Add structural-context.csv (World Bank WGI governance + WDI economy & education); document in DATA_DICTIONARY

DATA_DICTIONARY.md

@@ -64,3 +64,20 @@ Raw payload for the secondary "UK Election: Labour % of the vote?" market, kept
 ---
 
 **Sources:** [Wikipedia: Opinion polling for the 2024 United Kingdom general election](https://en.wikipedia.org/wiki/Opinion_polling_for_the_2024_United_Kingdom_general_election) · Polymarket "Which party wins the most seats after UK Election?". Maintained by [AFOS Analytics](https://afos-analytics.com). Data CC BY 4.0, code Apache 2.0.
+
+## `data/uk-structural-context.csv`
+
+Structural country context from the **World Bank**, complementary to the divergence data: it frames the country, it does **not** predict the electoral outcome. Long/tidy format, one row per indicator, latest available year per indicator.
+
+| Column | Type | Notes |
+|--------|------|-------|
+| `category` | string | `governance`, `economy`, or `education`. |
+| `indicator` | string | Machine code (e.g. `political_stability`, `gdp_usd`, `expected_years_schooling`). |
+| `label` | string | Human-readable indicator name (English). |
+| `value` | number | Governance on a 0–100 scale; economy in US$ / %; education in % of GDP or years. |
+| `unit` | string | `index_0_100`, `USD`, `percent`, or `years`. |
+| `year` | integer | Reference year of the value (latest available). |
+| `source` | string | World Bank WGI (governance, via Data360) or WDI (economy & education). |
+| `iso3` | string | ISO 3166 alpha-3 country code. |
+
+Both sources are open-licensed (CC BY 4.0) and keyless. Governance = Worldwide Governance Indicators; economy & education = World Development Indicators.

data/uk-structural-context.csv

@@ -0,0 +1,12 @@
+category,indicator,label,value,unit,year,source,iso3
+governance,political_stability,"Political stability",70.3,index_0_100,2024,"World Bank Worldwide Governance Indicators (WGI)",GBR
+governance,voice_accountability,"Voice and accountability",79.6,index_0_100,2024,"World Bank Worldwide Governance Indicators (WGI)",GBR
+governance,rule_of_law,"Rule of law",78.8,index_0_100,2024,"World Bank Worldwide Governance Indicators (WGI)",GBR
+governance,government_effectiveness,"Government effectiveness",74.4,index_0_100,2024,"World Bank Worldwide Governance Indicators (WGI)",GBR
+governance,regulatory_quality,"Regulatory quality",78.7,index_0_100,2024,"World Bank Worldwide Governance Indicators (WGI)",GBR
+governance,control_of_corruption,"Control of corruption",78.4,index_0_100,2024,"World Bank Worldwide Governance Indicators (WGI)",GBR
+macro,gdp_usd,"GDP (current US$)",3686033044482,USD,2024,"World Bank World Development Indicators (WDI)",GBR
+macro,gdp_per_capita_usd,"GDP per capita (current US$)",53246.37,USD,2024,"World Bank World Development Indicators (WDI)",GBR
+macro,inflation_pct,"Inflation, consumer prices (annual %)",3.27,percent,2024,"World Bank World Development Indicators (WDI)",GBR
+education,gov_expenditure_pct_gdp,"Government expenditure on education (% of GDP)",5.91,percent,2021,"World Bank World Development Indicators (WDI)",GBR
+education,expected_years_schooling,"Expected years of schooling",17.25,years,2018,"World Bank World Development Indicators (WDI)",GBR