The European Community Household Panel (ECHP) is a very ambitious project whose main purpose is to collect comparable economic, social and demographic information at the individual and the household level throughout the European Union (EU). An attractive feature of the ECHP is its comparability across countries and over time. Indeed, a great deal of effort was devoted to harmonizing the survey characteristics. Nevertheless, the design and the organization of the survey are not completely standardized across countries. This paper exploits the variability of the survey characteristics, both across countries and over time, in order to identify the effects of various features of the data collection process on survey participation. We focus attention on survey nonparticipations caused by ineligibility, contact failure or lack of cooperation. We analyze cross-country differences in participation rates trying to disentangle the role played by differences in the socio-demographic composition of the national populations and the differential characteristics of the data collection process.