Definition
Plain language
When a country's prices rise so fast that money loses meaningful value within weeks.
As stated in the literature
An extreme monetary regime — typically defined by month-over-month price increases above 50% — used in the inverse-scaling LLM forecasting paper as a regime-change test case (e.g., Brazil 1985-1989).
Why it matters: It's a clean test case for whether forecasting models recognize regime changes, because anyone extrapolating prior trends will be catastrophically wrong.
For example, in Brazil in the late 1980s, prices were rising so fast that menus and price tags had to be rewritten weekly.
Heard on the show
“It wrote out, in its own response — and I'm quoting almost verbatim — "hyperinflation could also stabilize through currency reform, adding downside uncertainty.”Episode 069 — When Smarter Models Forecast Worse: The Hidden Failure Mode in LLM Predictions