Who are the colleagues participating when asked to complete expert surveys? This research note investigates which individuals' characteristics associate with positive responses. Drawing on an expert survey dedicated to post-conflict trials, we collect data on various attributes of both respondents and non-respondents such as their age, sex, academic positions, disciplines, and research outputs. We expect that decisions to participate result from an interplay of (1) individuals' levels of context-specific expertise, (2) the value attached to their expert role, (3) their confidence in making authoritative statements, and (4) resource constraints. Employing logistic regression models and statistical simulations (n = 414), we find that context-specific expertise is the primary, but not the only determinant of participation. On the one hand and luckily, individuals whose research corresponds closely to the object of study are most likely to participate. On the other hand and unfortunately, individuals with high citation outputs, female experts, and Area Studies-scholars are less likely to respond. Consequently, certain groups are under-represented in expert evaluations frequently considered as authoritative source of knowledge.
