Embracing seasonality in national accounts data
Usually, if you have the choice, you want to look at macroeconomic data that have been seasonally adjusted. This adjustment lets you compare periods within any year without being misled by the various fluctuations that occur every year. Ice cream production, tourism, and toy purchases, for example, all have predictable seasonal factors, and usually we’re interested in what happens beyond these seasonal effects.
The same logic applies to aggregate measures such as gross domestic product (GDP). But, occasionally, we just want the raw data. All three GDP components shown in the graph above consistently dip in the first quarter. In most of the country, the winter months hinder activities such as residential construction and local government infrastructure projects. As for the dip in imports, that’s linked to the dips described above, because general declines in activity are definitely reflected in imports.
How this graph was created: From the gross domestic product release, go to section 8 (not seasonally adjusted); then choose the table with real GDP, select the relevant series, and click “Add to Graph.”
Suggested by Christian Zimmermann.
View on FRED, series used in this post: