Researchers in several countries have regularly reported decreasing response rates for surveys and the need for increased efforts in order to attain an acceptable response rate: two things that can be seen as signs of a worsening survey climate. At the same time, differences between countries and surveys with regard to the actual level and evolution of response rates have also been noted. Some of these differences are probably linked to differences in the survey content or design. This may hinder the study of the evolving survey climate over time, based on different surveys in different countries, because more readily …