Information and voting: Evidence from Peru's 2026 presidential election

Abstract

We study how election-night flash estimates shape voting in Peru's fragmented 2026 presidential election. We exploit a natural experiment: on April 12, 2026, 187 polling tables across 13 voting centers failed to install, and the \emph{Jurado Nacional de Elecciones} (JNE) extended voting for the affected $\approx\!55 000$ electors to Monday, April 13. These voters cast ballots after observing the Ipsos and Datum flash estimates; otherwise comparable Sunday voters did not. A Bayesian-updating model of multi-candidate plurality voting frames the analysis, yielding predictions about vote reallocation toward the three candidates the estimates rendered viable -- López Aliaga, Sánchez, and Nieto. We estimate treatment effects on candidate vote shares at both the \emph{acta} level and the acta-weighted polling-station level, comparing treated and control \emph{locales de votación} matched on pre-treatment covariates. How flash estimates reshape voting is of first-order importance for Peru, given its institutional instability and high political volatility over the past decade.