Sign me up! Promoting volunteering with a compound task mechanism

Building on theoretical and empirical literatures showing that choices not only reflect but also create preferences, we develop a two-stage compound task mechanism to promote pro-sociality. The first stage involves incentivizing participants to complete a compound task consisting of a targeted pro-social activity—volunteering– and a complement activity—writing about volunteering. The second stage involves incentivizing participants to repeatedly complete only the writing about volunteering. We conduct a field experiment and show that, conditional on completing first-stage volunteering + writing, intrinsic interest in volunteering is promoted even when people fail to complete the second-stage writing about volunteering. By contrast, participants assigned in the second stage either to volunteering, or to volunteering + writing, but who failed to complete these tasks, did not develop intrinsic interest in volunteering. These results are consistent with the theory underlying our two-stage compound-task mechanism.