How much is a US dollar worth? If you aren't talking about inflation, and if you're in the US, then that question seems a bit odd. But if you travel abroad, or if you're buying and selling goods abroad, then this question can actually be quite relevant. If the dollar is weak, then goods imported from other countries are expensive, and going to visit those countries costs more. (Plus, US goods become cheaper when imported into foreign countries.)
And indeed, the US dollar is weaker now than in quite some time, as the New York Times reported earlier this week (https://www.nytimes.com/2025/06/30/business/dollar-decline-trump.html). This seems to reflect nervousness among investors regarding the Trump administration's policies, especially those having to do with tariffs and the high levels of debt the proposed budget would create.
This week, we'll thus look at the value of the US dollar. Of course, the "value of the dollar" only means something in the context of other currencies, so we'll have to see how it's doing against a number of other currencies tracked by the Federal Reserve.
Data and five questions
This week's data comes from the Federal Reserve's tracker of foreign exchange rates (https://www.federalreserve.gov/releases/h10/20250630/), described as H.10 on the Fed's system. They have been tracking a number of different currencies against the US dollar for some time.
I used FRED to download all of the H.10 values that I could at https://fred.stlouisfed.org/release?rid=17 . I then asked to plot all of them, and downloaded a CSV file from that page of plots.
However, I seem to have maxed out FRED's downloading system; I only got from DTWEXBGS (broad index), DEXUSEU (dollar-euro), DEXJPUS (dollar-yen), DEXCHUS (dollar-yuan), DEXCAUS (dollar-Canadian dollar), DEXUSUK (dollar-pound), DEXKOUS (dollar-Korean won), DEXMXUS (dollar-Mexican peso), DEXVZUS (dollar-Venezuelan peso), DTWEXAFEGS (advanced foreign economy index), DEXINUS (dollar-Indian rupee), and DEXBZUS (dollar-Brazilian real). So those are the ones we'll look at.
Paid subscribers (including members of my LernerPython+data membership) can download my data file from the bottom of this message.
This week's learning goals include working with CSV files, dates and times, filtering, correlations, grouping, and plotting.
I'll be back tomorrow with my solutions. Meanwhile, here are my five tasks and questions:
- Read the data into a data frame. Make sure that the observation_date column is a datetime, which should then be set to the index. Which currencies have been tracked at the start of the Fed's data set? Which was the most recent currency to be added?
- The New York Times article said, "The dollar is off to its worst start to a year in more than half a century." Calculate the percentage drop in the "broad" index (DTWEXBGS) for the first six months of each year starting in 2020.