Countries

The largest share of APE papers study US policy, drawing on Census ACS, FRED, BLS, CDC, and Socrata data. A key sub-focus is the T-MSIS Medicaid Provider Spending dataset — the first-ever provider-level claims data covering all 50 states, DC, and U.S. territories from January 2018 through December 2024 (~227 million rows), released by HHS in February 2026. We also integrate FBI Crime Data Explorer data, providing county- and agency-level crime statistics for studying the effects of policing, sentencing, and criminal justice policies.

Integrated sources: Census ACS, FRED, BLS, Socrata, CDC, T-MSIS (Medicaid), FBI Crime Data

India is one of the most policy-rich developing countries, with dozens of large-scale government programs affecting hundreds of millions of people. The SHRUG dataset (Socioeconomic High-resolution Rural-Urban Geographic Platform, v2.1) provides the geographic backbone: stable identifiers for ~640,000 villages and ~8,000 towns, linked to Census, Economic Census, and satellite nightlight data spanning 1991–2021. Practical API access to official Indian administrative portals ( MGNREGA MIS, PLFS, NFHS/DHS, UDISE+, RBI DBIE) unlocks credible causal analysis of India's major development programs.

Integrated sources: SHRUG, MGNREGA MIS, PLFS, NFHS/DHS, UDISE+, RBI DBIE

France offers rich administrative data for policy evaluation, from property transactions (DVF) to firm registries (INSEE Sirene) and federal legislation timing (Légifrance). The research program starts with low-friction public sources and progressively adds authenticated APIs for deeper analysis.

Integrated sources: INSEE BDM/SDMX, DVF, Elections, Cadastre, RTE eCO2mix, Sirene, Légifrance

Switzerland's federal structure — 26 cantons and ~2,100 autonomous municipalities — creates exceptional natural experiments for policy evaluation. Staggered cantonal adoption of laws, direct democracy referendums, and wide municipal tax variation provide clean identification strategies.

Integrated sources: opendata.swiss, BFS PXWeb, Swissvotes, Fedlex SPARQL, SMMT

The UK combines exceptional administrative data depth with a federal-style structure that generates clean natural experiments. England's ~300 Local Authorities adopt policies (selective licensing, Council Tax support, Clean Air Zones) at different times, enabling staggered DiD. Devolved nation borders (Scotland, Wales, Northern Ireland vs. England) provide further policy discontinuities. Core sources are all open: the ONS Statistics API and NOMIS cover labour and demographics; HM Land Registry Price Paid Data covers 24M+ property transactions since 1995; the Police API and Environment Agency APIs provide crime and environmental data.

Integrated sources: ONS API, NOMIS, Land Registry PPD, EA Flood/Rainfall, Police API, Companies House, data.gov.uk CKAN

Nigeria's policy ecosystem combines high-frequency fiscal transparency data with procurement and health sources that are unusually useful for causal policy research. Public finance flows can be tracked via Open Treasury daily payment data, while procurement exposure can be measured from NOCOPO records. National health outcomes can be linked through NCDC reporting, with ACLED and DHS extending to conflict and household-level mechanisms.

Integrated sources: Open Treasury, NOCOPO, NCDC, World Bank APIs, ACLED, DHS, IATI

Papers studying policies outside the primary country programs, including cross-country comparative studies and other geographies.