in the Philippines. Local electoral contestation at the municipal level is not based on national party labels, but instead, is organized around local political families or “clans” (Hutchcroft and Rocamora, 2003; de Dios, 2007). These clans are described as relying on social networks through which politicians can identify which voters to target.

Finally, there appear to be other mechanistic ways in which local politicians are able to enforce vote buying contracts, because of the weak institutional environment. In anonymous interviews to the author, a group of local mayors (in another province) described in detail how they require voters to provide carbon copies of the ballot sheet to receive their payment. Similar narratives are also available in existing qualitative work (Schaffer, 2005). The election commission of the Philippines had not rolled out the use of electronic voting technology at the time of this study. More recent anecdotes seem to suggest the use of mobile phone cameras in enforcing the vote buying contract (Cruz, 2012).

Other literature on local politics in the Philippines suggests that the threat of violence may also be used, making it difficult for people to refuse to accept money or to vote differently (Sidel, 1999). The presence of an illegal economy in a municipality might simultaneously facilitate political access to the financing for vote buying, as well as to the means of enforcement through coercion. To capture this, the survey included questions on the experience of violence in local politics. The vast majority of respondents did not report any instances. Only two municipalities in the sample had a non-trivial number of respondents reporting instances of violence, and these municipalities also had the highest reported instances of vote buying. Clientelism and violence could be complementary political strategies at play in some areas where politicians can extract rents from illegal economic activity, and gain and remain in political office despite under-investment in pro-poor services.

# **3. Examining the sources of variation in vote buying**

The available theories of the conditions under which vote buying is selected as a political strategy are applied to examine the sources of variation across municipalities. A large number of specifications of the following general form were estimated, varying the composition of the explanatory variables contained in the **_X_** vector:

# VoteBuyingik = β0 + XikBb + εik(1)

The dependent variable in (1) is the proportion of households among those interviewed in village _i_ in municipality _k_ that answer affirmatively to different vote buying questions in the survey. The 20 household respondents in each village were asked the following questions: 1) “As far as you know, are there cases of vote buying in this municipality?” and 2) “Did someone offer you money for your vote?”. The percentage of respondents answering “yes” to these questions is separately aggregated up to the village and municipal level, for two different village or municipal level measures of the extent of vote buying politics, corresponding to each of these questions. On average, 38 percent of respondents in a village reported knowing about instances of vote buying, ranging from a minimum of no one reporting such cases, to a maximum of 94 percent of respondents reporting such cases. When asked directly about personal experience with being offered money in exchange for a vote, the reported instances fall substantially—only 18 percent 10