Many theories of policy diffusion contend that the flow of information is the driving force in the diffusion process. Prior scholarship has identified at least two types of information: information about policy and information about political viability. Few empirical approaches have been able to distinguish between these separate mechanisms. The authors argue that an analysis of policy proposals can untangle political information from policy-based information. They employ their strategy with data on the proposal of tax and expenditure limits (TELs) in the U.S. states since 1970 through direct democracy. The authors find that states in close geographic proximity to states that have rejected TELs are significantly less likely to propose TELs themselves. Since this event does not reveal information about policy effectiveness, the authors conclude that information about political viability systematically diffuses from state to state at the proposal stage of policy making.
