text: While at Penn , Phelps ' research focused mainly on the link between employment , wage setting and inflation , leading to his influential 1968 paper `` Money-Wage Dynamics and Labor Market Equilibrium '' .
simplified: While at Pennsylvania , most of Phelps ' research was on the links between employment , wages and inflation . He wrote about this in 1968 : `` Money-Wage Dynamics and Labor Market Equilibrium '' .