It is widely thought that lobbyists exert influence over legislators’ policy positions and, as a result, over policy outcomes. One mechanism of influence is the provision of policy expertise. Yet, there is little credible empirical evidence that lobbyists’ expertise influences legislative outcomes. Across four experiments fielded with three lobbyists in two state legislatures that examine two public measures of legislators’ positions, we find no evidence that lobbyists’ expertise influences legislators’ policy positions. We do find, in contrast, that the same policy expertise treatment is influential when provided by a legislative staffer. We conclude that policy information can influence legislators’ positions, but that legislators are cautious when that information is provided by lobbyists.

We report the results of a field experiment conducted in New York City during the 2013 election cycle, examining the impact of nonpartisan messages on donations from small contributors. Using information from voter registration and campaign finance records, we built a forecasting model to identify voters with an above-average probability of donating. A random sample of these voters received one of four messages asking them to donate to a candidate of their choice. Half of these treatments reminded voters that New York City's campaign finance program matches small donations with public funds. Candidates’ financial disclosures to the city's Campaign Finance Board reveal that only the message mentioning policy (in generic terms) increased donations. Surprisingly, reminding voters that matching funds multiplied the value of their contribution had no effect. Our experiment sheds light on the motivations of donors and represents the first attempt to assess nonpartisan appeals to contribute.