What We Can Learn about the Behavior of Firms from the average Monthly Frequency of Price-Changes: An Application to the UK CPI Data

In this paper, we see how much the average monthly frequency of price changes ties down the behavior of firms in steady-state in terms of the average length of price-spells across firms. We use the UK CPI data at the aggregate and sectoral level and find that the actual mean is about twice the theoretical minimum consistent with the observed frequency. We estimate the distribution using the hazard function and find that, despite the micro differences, the artificial Calvo distributions generated using the sectoral frequencies result in very similar impulse responses to the estimated hazards when used in the Smets-Wouters (2003) model.