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

DATA_DICTIONARY.md

@@ -58,3 +58,20 @@ Raw Polymarket payload (event + per-party price histories), via a US-resolving f
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 **Sources:** [Wikipedia — Opinion polling for the 2025 German federal election](https://en.wikipedia.org/wiki/Opinion_polling_for_the_2025_German_federal_election) · Polymarket "Germany Parliamentary Election Winner". Maintained by [AFOS Analytics](https://afos-analytics.com). CC BY 4.0.
+
+## `data/germany-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/germany-structural-context.csv

@@ -0,0 +1,12 @@
+category,indicator,label,value,unit,year,source,iso3
+governance,political_stability,"Political stability",68,index_0_100,2024,"World Bank Worldwide Governance Indicators (WGI)",DEU
+governance,voice_accountability,"Voice and accountability",84.8,index_0_100,2024,"World Bank Worldwide Governance Indicators (WGI)",DEU
+governance,rule_of_law,"Rule of law",84.9,index_0_100,2024,"World Bank Worldwide Governance Indicators (WGI)",DEU
+governance,government_effectiveness,"Government effectiveness",81.4,index_0_100,2024,"World Bank Worldwide Governance Indicators (WGI)",DEU
+governance,regulatory_quality,"Regulatory quality",78.5,index_0_100,2024,"World Bank Worldwide Governance Indicators (WGI)",DEU
+governance,control_of_corruption,"Control of corruption",83.8,index_0_100,2024,"World Bank Worldwide Governance Indicators (WGI)",DEU
+macro,gdp_usd,"GDP (current US$)",4685592577805,USD,2024,"World Bank World Development Indicators (WDI)",DEU
+macro,gdp_per_capita_usd,"GDP per capita (current US$)",56103.73,USD,2024,"World Bank World Development Indicators (WDI)",DEU
+macro,inflation_pct,"Inflation, consumer prices (annual %)",2.26,percent,2024,"World Bank World Development Indicators (WDI)",DEU
+education,gov_expenditure_pct_gdp,"Government expenditure on education (% of GDP)",5.24,percent,2022,"World Bank World Development Indicators (WDI)",DEU
+education,expected_years_schooling,"Expected years of schooling",16.93,years,2018,"World Bank World Development Indicators (WDI)",DEU