Are samples drawn from Mechanical Turk valid for research on political ideology?

Amazon's Mechanical Turk (MTurk) is an increasingly popular tool for the recruitment of research subjects. While there has been much focus on the demographic differences between MTurk samples and the national public, we know little about whether liberals and conservatives recruited from MTurk share the same psychological dispositions as their counterparts in the mass public. In the absence of such evidence, some have argued that the selection process involved in joining MTurk invalidates the subject pool for studying questions central to political science. In this paper, we evaluate this claim by comparing a large MTurk sample to two benchmark national samples - one conducted online and one conducted face-to-face. We examine the personality and value-based motivations of political ideology across the three samples. All three samples produce substantively identical results with only minor variation in effect sizes. In short, liberals and conservatives in our MTurk sample closely mirror the psychological divisions of liberals and conservatives in the mass public, though MTurk liberals hold more characteristically liberal values and attitudes than liberals from representative samples. Overall, our results suggest that MTurk is a valid recruitment tool for psychological research on political ideology.