Inflation persistence: how much can we explain?

Until recently most macroeconomic models in which monetary policy has real effects were based on the assumption that agents in the economy do not use all available information when making a decision. Critics of these models argue that this assumption implies that agents are not rational. ; In response to this criticism, a class of New Keynesian models has recently been proposed. These models combine \"old\" Keynesian elements with an environment in which agents form their expectations rationally. The simplest version of such models includes only one type of nominal rigidity, either sticky prices or sticky wages-that is, prices or wages that adjust only slowly to market shortages or surpluses. But these simple models have a drawback: They do not seem to be able to reproduce the persistence of inflation observed in the data. ; This article explores whether adding sticky wages to the baseline sticky-price model solves the persistence-of-inflation problem when plausible durations of price and wage contracts are assumed. ; The analysis confirms that the baseline sticky-price model cannot replicate the observed inflation persistence unless an implausible degree of either price stickiness or exogenous nominal interest rate persistence is assumed. The findings also show that a model with both sticky prices and sticky wages can replicate more closely the autocorrelation function of inflation, even with acceptable levels of both price and wage stickiness.