The spread of misinformation has been linked to increased social divisions and adverse health outcomes, but less is known about the production of disinformation, which is misinformation intended to mislead. In a field experiment on MTurk (N = 1,197), we found that while 70 % of workers accepted a control job, 61 % accepted a disinformation job requiring them to manipulate COVID-19 data. To quantify the trade-off between ethical and financial considerations in job acceptance, we introduced a lower-pay condition offering half the wage of the control job; 51 % of workers accepted this job, suggesting that the ethical compromise in the disinformation task reduced the acceptance rate by about the same amount as a 25 % wage reduction. A survey experiment with a nationally representative sample shows that viewing a disinformation graph from the field experiment negatively affected people's beliefs and behavioral intentions related to the COVID-19 pandemic, including increased vaccine hesitancy. Using a "wisdom-of-crowds" approach, we highlight how online labor markets can introduce features, such as increased worker accountability, to reduce the likelihood of workers engaging in the production of disinformation. Our findings emphasize the importance of addressing the supply side of disinformation in online labor markets to mitigate its harmful societal effects.