What Is Happening to the New Greek National Accounts Data?

In 2020, the Hellenic Statistical Authority (ElStat) started a revision of the national accounts for Greece to bring them into line with the new European System of Accounts. Data from national accounts have gained more relevance as a crucial set of information for policy, especially in the eurozone, since many indicators--like the size of the public deficit relative to GDP--depend on them. It is therefore crucial that these data provide a realistic description of the actual state of the economy. Models that aim at understanding the medium-term trajectory of an economy usually need to abstract from short-term volatility due to the seasonal behavior of some variables, and it is therefore common practice to use seasonally adjusted data rather than the observed seasonal data. Research Scholar Gennaro Zezza, Institute President Dimitri Papadimitriou, and Research Associate Nikos Rodousakis recently noticed that the dynamics of relative prices, as measured by the ratios between the deflators of the different seasonally adjusted components of GDP, had an excess volatility, which made it more difficult to obtain meaningful econometric estimates of their determinants. They have therefore decided to investigate whether this excess volatility could be observed in the original seasonal data, and this note documents their results.