Roman law in the dark ages I read from Leonard Mlodinow The Drunkard’s Walk: How Randomness Rules Our Lives, was based on the practice of Germanic tribes. Things were somewhat different to what we are now familiar with – but there are similarities. The rules of testimony are a case in point.
The veracity of a husband’s denial of the claim that he was having an affair with his wife’s toga maker would have been determined not by his performance in front of a prickly opposing counsel but by whether he would stick to his story after being poked with a red hot iron.
Mlodinow – a statistician rather than an economist notes that bringing back that custom would likely increase the number of out of court settlements dramatically.
Incentives mattered to Romans too.