The graph above tracks gasoline prices in Europe and the U.S. An American looking at the graph may be puzzled by the much smaller decline in Europe than in the U.S. Why the difference? One reason is that taxes on fuel are much higher in Europe, which means that a large fraction of the cost there hasn’t changed. The graph below shows another reason: The price of crude oil in euros actually hasn’t changed that much. The dollar price has declined a great deal, but the dollar has also strengthened significantly with respect to the euro, canceling out much of the decline. Indeed, the dollar price fell from about $110 to about $50. The euro price fell much less, from €80 to €50.

How these graphs were created: For the first graph, search for “europe transportation fuel price” and “gasoline CPI” (monthly, not seasonally adjusted) and add the series. To align both series at the recent peak price for the U.S., choose “Index (Scale value to 100 for chosen period)” for the units and 2014-06-01 for the date. For the second graph, search for “oil Brent” and select the monthly series. Then add the same series again as series 2. Finally, add the dollar/euro exchange rate to series 1 and apply transformation a/(b). (The parentheses in the formula simply make the label in the graph easier to read.)

Suggested by Christian Zimmermann.