[!todo] Seed note. A starting point, not a finished note yet.
Most technologies follow a learning curve: each doubling of cumulative production cuts unit cost by a roughly constant percentage, because firms accumulate experience, standardize, and scale. A negative learning curve is the rare inversion, where cost rises with cumulative build. US nuclear power is the canonical case, with real per-plant construction costs climbing several-fold after about 1970 instead of falling. The debated causes, regulatory ratcheting, loss of design standardization, and financing structure, matter because each points to a different fix, and the same dynamics now shadow whether small modular reactors can break the pattern. Seeded from Nuclear Energy.