The distribution of cash for votes is effective in mobilising voters to participate in elections; and it tends to favour opposition politicians, who are less equipped with state resources. These are the central findings of research by Professor Pedro Vicente, published in the February 2014 issue of the Economic Journal.


His study involved a field experiment during presidential elections in 2006 in the West African island nation of Sao Tome and Principe, a country that saw a sizeable increase in vote-buying after oil was discovered there at the end of the 1990s.


Working with the national electoral commission, a civic education campaign was launched focused on counteracting vote-buying. The campaign was conducted in randomly chosen parts of the country, and a control group was established in other locations to enable comparability.


Among the findings:


· The civic education campaign reduced people''s perceptions that voting decisions were affected by the money offered by candidates; and it increased reports that voting was conducted in good conscience. Both represent a significant fall in the effectiveness of vote-buying.


· In terms of actual voter behaviour at the polls as measured by official results, the civic education campaign led to a reduction in voter turnout (by 3-6 percentage points), a rise in the vote share of the incumbent and a fall in the vote share of the challenger (both by close to 4 percentage points). These effects are confirmed in survey data at the individual level.


· Informed by the negative impact of the voter education campaign on the effectiveness of vote-buying, the results on voter behaviour point to a positive effect of vote-buying on participation and to greater reliance of challengers (relative to incumbents) on vote-buying practices.


The author interprets these implications as being consistent with an incumbency advantage, possibly stemming from the greater ability of incumbents to engage in such practices as promising public sector jobs to voters.


He concludes with a note of caution:


''On the one hand, it may be argued that vote-buying leads to worse public policies by being a substitute for the provision of public goods.


''On the other hand, my study finds that vote-buying is likely to benefit challengers (and electoral competition) and increase political participation.


''Taken in isolation, these findings may be regarded as positive. But improved electoral competition can only help development if there is real policy accountability – and it is unlikely that vote-buying helps policy accountability.''


''Is Vote-buying Effective? Evidence from a Field Experiment in West Africa'' by Pedro Vicente is published in the February 2014 issue of the Economic Journal. Pedro Vicente is at the Nova School of Business and Economics at the Universidade Nova de Lisboa.