Do Biometric Identification Machines Help to Clean Up Elections. Evidence from Colombia

Biometric identification machines (BIMs) are part of a new set of tools available to prevent electoral fraud. These machines allow electoral authorities to tackle the impersonation of voters and the illegal substitution of poll workers, and are currently used in approximately 40 countries. This paper investigates the electoral consequences of BIMs and whether political parties use other kinds of electoral fraud to compensate for the potential effects of the new controls. Taking advantage of their partial deployment in elections to department assemblies in Colombia, I find that the presence of BIMs, on average, increased the vote shares of incumbent legislators in municipalities that are governed by mayors in same political party. Strong local parties strategically evade BIMs and use aggregation fraud to compensate for potential losses in their strongholds. Meanwhile, voters’ experiences with vote buying and intimidation were unchanged. By highlighting unintended consequences of anti-fraud interventions, my findings corroborate the importance of comprehensive strategies to ensure electoral integrity to avoid that well-connected politicians are able to circumvent controls.


Working Paper