The FRED Blog has discussed how the timing of harvesting seasons results in predictable changes in the prices of fresh crops in the United States. Today, we use data on harmonized consumer prices indexes (HICPs) to compare seasonal upswings and downswings in vegetable prices in different countries across the European Union (EU).

The HICPs are directly comparable across all countries of the EU because they are calculated according to harmonized definitions. So, whether it’s called potato, potatoe, or patata, the product category for vegetables follows the European classification of individual consumption according to purpose (ECOICOP) and by goods and services.

The FRED graph above shows the HICPs for vegetables in four European countries: Poland (the blue line); Spain (the red line); Italy (the green line); and Latvia (the purple line). The data are reported by Eurostat and all four price index series have the same base period of January 2015.

Regular and large increases and decreases in consumer price indexes for vegetables in Poland and Latvia contrast with much smaller upswings and downswings in Spain and Italy. What gives? In Europe, northern countries record, on average, lower temperatures and less direct sunlight than southern countries, so their growing seasons for vegetables are relatively shorter. That makes their overall supply relatively small and drives prices up. At the same time, industrial agriculture in the southern countries supplements regional deficits in water, humidity, and nutrients, increasing their crop yields and driving prices down. In short, the climate conditions during the year have more marked seasonal effects on vegetable prices in those countries with a more constrained local supply. Those seasonal patterns are even more noticeable when we plot the percent change in the price indexes.

How the graph was created: Search FRED for and select “Harmonized Index of Consumer Prices: Vegetables for Poland.” Next, click on the “Edit Graph” button and use the “Add Line” tab to search for and add “Harmonized Index of Consumer Prices: Vegetables for Spain.” Repeat the previous step to add “Harmonized Index of Consumer Prices: Vegetables for Italy” and “Harmonized Index of Consumer Prices: Vegetables for Latvia.”

Suggested by Diego Mendez-Carbajo.