Incentives, lies, and disclosure

Summary. Prosecutors can force witnesses to testify and use perjury prosecutions to hold them to the provable truth. More controversially, prosecutors also offer witnesses inducements for favorable testimony, including leniency, immunity, and even cash. This ubiquitous behavior would be illegal as witness bribery, except for a longstanding tradition of sovereigns using this power, which legal doctrine now reflects. A causal analysis shows that even if prosecutors use this power only in good faith, these inducements undermine the epistemic value of witness testimony.