Quadrivium: Reconstructive Harmonization of U.S. Higher-Education Survey Data — HERD Financial and Personnel Panels

Reproducible analytical panels harmonizing NSF Higher Education Research and Development (HERD) survey data (FY 1972–2024) across the 2010 instrument redesign, using Reconstructive Harmonization: each era is reconstructed on its own terms, the era boundary is decomposed into named, quantified components (real growth, definitional change, population expansion, bounded residual), and both are published with documentation a cold reader can use without misreading the discontinuity. The deposit ships a 50-year field-level R&D expenditure panel (FY 1975–2024), a Q15/Q16 research-personnel panel (FY 2022–2024), and a Q4/Q5 attribute sibling, each validated against published NSF/NCSES ground truth.