Perfect Bayesian Equilibrium in Signaling Games: The Case of Credential Inflation in the Job Market

In modern labor markets, rising educational attainment among job applicants often fails to translate into corresponding productivity differences. This phenomenon, commonly referred to as credential inflation, raises concerns about the signaling power of education. This paper explores credential inflation through the lens of signaling games in microeconomic theory and investigates how changing cost structures and labor market screening contribute to inefficient signaling. Specifically, a Perfect Bayesian Equilibrium (PBE) model is used, where job applicants privately know their ability level and choose their education level to signal productivity to employers. When the cost of education becomes less sensitive to ability, pooling equilibria emerge, where both high- and low-ability workers choose the same level of education. As a result, education loses its signaling power and inflation of educational requirements occurs. This paper concludes that credential inflation is a rational outcome under certain market conditions and propose policy responses to mitigate its effects on labor market sorting.