Do truth-telling oaths improve honesty in crowd-working?

Abstract

This study explores whether an oath to honesty can reduce both shirking and lying among crowd-sourced internet workers. Using a classic coin-flip experiment, we first confirm that a substantial majority of Mechanical Turk workers both shirk and lie when reporting the number of heads flipped. We then demonstrate that lying can be reduced by first asking each worker to swear voluntarily on his or her honor to tell the truth in subsequent economic decisions. Even in this online, purely anonymous environment, the oath significantly reduced the percent of subjects telling "big" lies (by roughly 27%), but did not affect shirking. We also explore whether a truth-telling oath can be used as a screening device if implemented after decisions have been made. Conditional on flipping response, MTurk shirkers and workers who lied were significantly less likely to agree to an ex-post honesty oath. Our results suggest oaths may help elicit more truthful behavior, even in online crowd-sourced environments.

Fig 1. Flipping time distributions by treatment.

Note. Panels (a) and (b) display the empirical distribution of flipping times, by treatment. A red vertical line is drawn at 30 seconds—the threshold defining shirkers. 35 workers who spent more than 200 seconds on the coin-flipping question were dropped to construct these figures. Panel (c) reports the QQ-plot of the quantiles of the NoOath flipping time distribution (on the x-axis) against the Oath one (on the y-axis).

Fig 2. Heads flipped by flipping time and treatment.

Note. Each figure provides the empirical distribution of heads reported, along with the theoretical truthful distribution. The shaded bars highlight the density of respondents who report having flipped 10 heads. The p-value from Shapiro-Wilk tests of the null hypothesis that each distribution is similar to the normal distribution is <.001 for both the overall distribution and the distribution conditional on the report being lower than 10.

Fig 3. Empirical distribution of survey duration, by treatment.

Note. The left-hand side figures report the empirical distribution of survey overall duration, net of flipping time. To ease readability, 13 workers for whom this duration is higher than 1000s were dropped to construct these figures. The figure on the right-hand side displays the QQ plot of the deciles of the net survey duration in the NoOath treatment (on the x-axis) against the Oath one (on the y-axis).