NBER Publications by Martin Berka

We study a newly released data set of scanner prices for food products in a large Swiss online supermarket. We find that average prices change about every two months, but when we exclude temporary sales, prices are extremely sticky, changing on average once every three years. Non-sale price behavior is broadly consistent with menu cost models of sticky prices. When we focus specifically on the behavior of sale prices, however, we find that the characteristics of price adjustment seems to be substantially at odds with standard theory.

We study a newly constructed panel data set of relative prices of a large number of consumer goods among 31 European countries. We find that there is a substantial and non-diminishing deviation from PPP at all levels of aggregation, even among eurozone members. However, real exchange rates are very closely tied to relative GDP per capita within Europe, both across countries and over time. This relationship is highly robust at all levels of aggregation. We construct a simple two-sector endowment economy model of real exchange rate determination. Simulating the model using the historical relative GDP per capita for each country, we find that for most (but not all) countries there is a very close fit between the actual and simulated real exchange rate.

The national terms of trade, defined as the ratio of an export price index to an import price index has been extensively studied empirically. In this paper we construct an alternative measure, which we call the consumption terms of trade. This measure recognizes the fact that consumers and firms face different prices for the same items and consume different items. Using micro-data from the Economist Intelligence Unit at the retail level, we conduct a forensic analysis of the variation of the terms of trade of 38 countries. Using a novel variance decomposition method, we find that the bulk of terms of trade variation is accounted for by oil, automobiles and medicine. The other goods in our construct tend to exhibit balanced trade, providing a natural hedge against world price fluctuations. ...