This article discusses the microeconomic foundations of the concept of jurisdictional uncertainty. According to Arida et al (2005), Brazilian judges tend to favor the weak part in the claim, not the just, as a form of social justice. A utility function is discussed, taking into account the advantages the judge could gain from this behavior, outweighed by the penalties such as professional criticism and the reversal by a higher court.

An empirical test is conducted, analyzing 181 judicial decisions, and the results are supportive to the main ideas, showing that a contract has 45% more of chances of being maintained if it is beneficial to the richer.