Keynote Edith de Leeuw

Declining response rates are an ongoing source of concern for decades and publications documenting international nonresponse date back to the turn of this century (e.g. De Heer, 1999). The first studies tried to describe and explain nonresponse trends, discerning between noncontact and refusal rates. Coping strategies included refusal conversion and basic adjustment. In the 21^st century the focus shifted to the assessment and reduction of nonresponse bias and representativity, tailored survey designs, mixed-mode strategies, and combining data from different sources (De Leeuw, Luiten, & Stoop 2020).

Central in both reducing and adjusting for nonresponse is knowledge about important factors influencing the propensity to respond. These include both factors that are under the direct control of the researcher (e.g., mode choices, survey design, communication) and outside the direct control of the researcher (e.g. attributes of potential respondents, topic including difficulty of response task, and social environment, including survey climate). Although many factors are not under the direct influence of the researcher, the negative influence of certain factors on response propensity may be reduced by clever design (e.g. adaptive designs, special modes for special groups, structure of request, adaptation of questionnaire, selective incentives).

Despite much research effort into response enhancing methods, trend studies over the years showed that response rates are declining. However, although almost all counties show a clear decreasing trend, trends do differ between different countries, and some countries show a steeper decline over the years than others. These differences in nonresponse trends over countries can be explained only partially by differences in survey design and field methods between countries.

In the scientific literature on nonresponse survey general attitudes towards surveys and survey climate are often named as important theoretical concepts for explaining nonresponse (e.g. Loosveldt & Joye, 2016). However, trend analyses of attitudes towards surveys are scant, calling for an international survey climate barometer. The relative lack of empirical data on survey climate and its contextual effect on nonresponse rates is mainly due to the absence of a brief and reliable measurement instrument. To fill this gap, the Survey Attitude Scale was developed (de Leeuw, Hox, Silber, Struminskaya, & Vis, 2019). This scale has been used in Germany and the Netherlands, and is now implemented in the first and the last wave of the CRONOS-2 panel, a probability based online panel that is fielded in 12 European countries.

In the first part of this presentation I will briefly review studies into nonresponse trends and discuss known determinants of survey nonresponse. In the second part, I will describe the development of the Survey Attitude Scale. I will end with a description of the CRONOS-2 implementation.