The case study is based on an empirical analysis, which focuses on the effect of local direct democracy on turnout in elections in the Czech Republic. First, the methodological caveats of studying the effect of direct democracy on political engagement are explained. Second, the research design of panel data analysis is explained in detail. As the analysis relied heavily on secondary data from various different sources, it is described how the data were obtained and put together. We also provide a detailed description of all important variables that were included in the analysis. Last, the strategy we used in the panel data analysis, including the way we presented the results of our research, is exhibited. The case study should be helpful to anyone considering using panel data analysis as well as anyone using secondary data in empirical research in political science.