This paper explores the connection between inflation and unemployment in two different models with fair wages in both the short and the long runs. Under customary assumptions regarding the sign of the parameters of the effort function, more inflation lowers the unemployment rate, albeit to a declining extent. This is because firms respond to inflation—which spurs effort by decreasing the reference wage—by increasing employment, thus maintaining the effort level constant as implied by the Solow condition. A stronger short-run effect of inflation on unemployment is produced under varying as opposed to fixed capital, given that in the former case the boom produced by a monetary expansion is reinforced by an increase in investment. Therefore, I provide a new theoretical foundation for recent empirical contributions that find negative long- and short-run effects of inflation on unemployment.