Measuring the Effects of Consensus-building Processes with Methods of Intervention Research

In recent years, both environmental policy and research have emphasized the importance of involving the public in decision-making. This push for more participation is driven by considerable optimism about its ability to improve the quality of decisions and developments. There is, however, a lack of empirical research to support this assumption. The few studies that have attempted to measure the effect of public participation are of limited validity, as they were based on ex-post data mainly gained from expert assessments or document analysis. This paper reports on a recent study to measure and compare the effect of two consensus-building processes in a systematic and reliable way. This involved developing a new evaluation method based on the methodology of intervention research in environmental psychology. It was tested and applied in this study with two similarly designed consensus-building processes conducted in two neighbouring valleys of the Eastern Swiss Alps. These evaluation experiments showed that (a) the new evaluation method can measure and compare the effects of consensus-building processes in a differentiated and reliable way; and (b) consensus-building processes have systematic and partly statistically significant effects (at least in the short term) on several aspects of regional consensus. The initial results suggest that this new evaluation method is a promising way of obtaining reliable evidence about the societal effects of participatory processes.