RESUMEN

Psychologists and other social scientists increasingly conduct experiments with online convenience samples from Amazon's Mechanical Turk Marketplace (MTurk). MTurk and population-based samples differ in well-documented ways, but whether or not compositional differences are problematic for experiments remains controversial. We highlight a critically important characteristic that is likely to interact with many experimental treatments in the psychological and behavioral sciences, and that has not been identified by other studies of MTurk samples: economic anxiety. We document a sizable difference between contingent survey workers and the general population and explain the ways in which economic anxiety is likely to interact with experimental treatments. In an era of rapidly growing economic anxiety and group disparities in economic wellbeing, awareness of this compositional difference is essential, especially in cases where experimental stimuli may interact with economic anxiety. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12144-021-02535-4.