Runoff comebacks in comparative perspective. Two-round presidential election systems

In many countries, the president of the republic is directly elected through popular vote. Most such nations have an electoral system that provides for a double-round of voting. Often termed a two-round system, such elections have a second turn if no candidate obtains an absolute majority in the first round. This article presents an original dataset covering all the presidential and the semi-presidential regimes (73 countries) that have adopted two-round system along with the results of 423 elections for both the first and second round and whether the result was determined in the first round, whether the plurality winner of the first round was victorious in the second round, or whether there was a second round ‘comeback’ – when the runner-up of the first round was victorious in the second. A variety of exploratory hypotheses are presented that try to predict the likelihood of a second round or a comeback. Few are validated. The presence of an incumbent and a qualified method of presidential selection increases the probability of a second round occurring while a greater number of candidates and greater electoral volatility make it less likely. We find that no variables related to political institutions, presidential resources, or the structure of the first round predictive of a second round comeback. We make the dataset public so that future scholars can continue this form of investigation.