BRIEFS / CAUSAL SCIENCE IN U.S. HEALTHCARE
Causal science, weekly.
A weekly analysis of one question in U.S. healthcare, drawn from public data. Each brief presents the finding, the data and methods behind it, and the limits of what can be inferred.
Briefs report original analyses of publicly available data from federal agencies and professional organizations, including NRMP, AAMC, HRSA, ECFMG, CMS, and the Census Bureau. Each brief states its data sources, methods, and limitations, and the extracted tables are published alongside it. Causal inferences are drawn only where the study design supports them. New briefs are published weekly; an RSS feed is available.
DATA BRIEF / 20 September 2026
One in four APL citations in Medi-Cal plan policies points to a replaced letter
Across 2,525 citations of DHCS All Plan Letters in Local Health Plans of California policies, 37 percent cite a letter DHCS has since superseded, and 26 percent cite the old letter with no reference to its replacement.
DATA BRIEF / 13 September 2026
Who is filling family medicine residencies?
Family medicine offered 575 more residency positions in 2026 than in 2022. Every U.S.-based applicant group matching into it declined. Non-U.S. citizen international medical graduates more than doubled, and unfilled positions still nearly doubled.
Corrections welcome. Every number links to a published table or a CSV in this repository. If a figure is wrong or a better source exists, tell us and the brief will be updated with a note.