<P> There are at least two different mathematical derivations of the Phillips curve . First, there is the traditional or Keynesian version . Then, there is the new Classical version associated with Robert E. Lucas, Jr . </P> <P> The original Phillips curve literature was not based on the unaided application of economic theory . Instead, it was based on empirical generalizations . After that, economists tried to develop theories that fit the data . </P> <P> The traditional Phillips curve story starts with a wage Phillips Curve, of the sort described by Phillips himself . This describes the rate of growth of money wages (gW). Here and below, the operator g is the equivalent of "the percentage rate of growth of" the variable that follows . </P> <Dl> <Dd> g W = g W T − f (U) (\ displaystyle gW = gW ^ (T) - f (U)) </Dd> </Dl>

According to the phillips curve what are causes for inflation in the short run