Measuring Policy Diffusion with Automated Content Analysis: The case of Smoking Bans in Switzerland and the United States

Policy diffusion means that policies spread across countries, states, cantons, etc. For example, many cantons in Switzerland adopted smoking bans after an overwhelming majority supported them in a referendum in Ticino. Similarly, smoking bans spread quickly among U.S. states after their successful introduction in California. Many studies have documented the diffusion of policies, but few could explain it precisely.

Our main goal is to improve the understanding of policy diffusion by applying new statistical methods allowing to analyze very large quantities of text. Concretely, we want to find out whether and how the perception of smoking bans in one canton (respectively, U.S. state) is shaped by their adoption in other cantons (respectively, other U.S. states). An hypothesis is that implementation problems, or possible negative consequences for restaurants, are perceived differently when other cantons or states have had positive experiences with smoking bans. This procedure could be applied in many other areas and, therefore, it could make a significant impact on diffusion research. Our study will generate new, important knowledge on how smoking bans have spread, as well as on policy diffusion in general. Diffusion processes can speed up, or slow down, the nation-wide adoption of policies. Therefore, understanding policy diffusion is important for many different political actors.