Our Gemara on Amud Beis explores which claim a plaintiff prioritizes when he is claiming both: a fixed fine (kenas), dismissible if the defendant confesses, or damages requiring appraisal (e.g., pain, embarrassment), guaranteed with evidence. This affects whether witnesses denying testimony under oath incur a sacrificial obligation, applicable only to monetary claims. Rabbi Shimon holds people prioritize fixed fines, while the Rabbis believe they focus on guaranteed damages:

Rabbi Shimon holds: A person does not forgo a claim to something with a fixed value, such as a fine, and claim something whose value is not fixed and requires a financial appraisal, such as the cost of humiliation and degradation. And the Rabbis hold that one does not forgo a claim to something that the defendant is not exempt from paying if he admits his guilt, and claim something that the defendant is exempt from paying if he admits his guilt, such as a fine.

This reflects behavioral economics, particularly loss aversion, as studied by Daniel Kahneman and Amos Tversky (Econometrica, 1979, cited in Wikipedia: Loss Aversion). People fear losses more than they value equivalent gains, choosing safer options. For example, given Option A ($1,500 at 33%, $1,400 at 66%, $0 at 1%) or Option B (guaranteed $920), most choose Option B to avoid the 1% risk of loss, despite Option A’s higher expected value. The endowment effect, where people value owned goods more highly, explains why retailers frame incentives as “avoiding a $5 surcharge” rather than “a $5 discount” to leverage loss aversion.

Rabbi Shimon’s view aligns with preferring the certainty of a fixed fine, while the Rabbis’ stance reflects valuing guaranteed payments, despite uncertain amounts. These insights show emotional biases, like fear of loss, drive decisions. Understanding these tendencies helps us balance emotional impulses with logic, questioning whether our choices are as rational as we believe.