Sweet Crude: How Brazil's Flex Mills Turn Oil into Food Crises

Brazil's flex mills can switch between sugar and ethanol within a single season. When oil rises, ethanol becomes more profitable, sugarcane is diverted from sugar to fuel, global sugar supply tightens, food prices spike in import-dependent economies, and political feedback alters the very mandates that drove the response. The prediction reshapes the system it predicts. This paper applies George Soros's theory of reflexivity—developed for financial markets—to agricultural commodity systems. It maps the institutional architecture (CONSECANA, RenovaBio/CBIO, the E30 mandate, ICE No. 11 versus CEPEA/ESALQ pricing), models the flex decision quantitatively, and traces the reflexive feedback loop through four historical cycles spanning 2006–2026, including the 2009–2011 episode that ended with 36-cent sugar and a federal mandate cut. The cycle's periodicity is roughly 3–5 years; its amplitude is sufficient to swing the global sugar balance from surplus to deficit. The paper closes with falsification criteria tied to observable UNICA, BRL/USD, and corn ethanol thresholds. The contribution is structural: Brazilian mill operators, responding rationally to local price signals, function as an institutional bridge transmitting Persian Gulf volatility into food costs in Cairo, Dhaka, and Jakarta.