Between 1918 and 1920, the Consumer Price Index went from 15.1 to 20.
Cumulatively, prices increased 32.5%, which works out to an average of
15.09% per year. Put differently, a dollar in 1918 bought what
$0.76 buys in 1920.
1918 brought the steepest annual price increase the CPI had recorded:
consumer prices rose 18.0% for the year, edging out 1917’s already sharp
17.4% as the economy stayed at full wartime mobilization for most of the
year. A first-class stamp cost 3 cents, up from 2 cents the previous
November under the War Revenue Act’s wartime tax increases. The war itself
ended on November 11, when Germany signed an armistice with the Allied
powers after more than four years of fighting in Europe, but the inflation
built up over a year and a half of mobilization did not disappear along with
the fighting. The bigger public health story that year was the influenza
pandemic that reached the U.S. in a mild spring wave and then returned that
fall in a far deadlier form, eventually killing roughly 675,000 Americans,
more than the country’s combat losses in the war. It hit factories, docks,
and shops alongside households, adding disruption to an economy already
strained by wartime demand. Prices would keep climbing even after the
armistice, into the postwar surge of 1919.
The headline number is an average. Individual categories moved very differently over this
period. Here is what $100 of 1918 spending costs in 1920, by category:
Category
Avg. yearly inflation
$100 in 1918 →
All items (CPI-U)
15.09%
$132
Apparel
25.65%
$158
Food
12.14%
$126
Not shown because the BLS began these indexes after 1918: core (all items less food & energy) (1957–), energy (1957–), housing (1967–), medical care (1935–), transportation (1935–), recreation (1993–), education & communication (1993–).
1920 was the last year of the inflation that had built since the war began:
consumer prices rose 15.6% for the year, leaving the CPI more than double its
1913 starting level after seven straight years of increases.
The boom behind those increases turned to bust before the year was over. The
Federal Reserve, worried about speculation, pushed its discount rate to a
record 7% that spring, and wholesale prices, which had led the wartime
runup, began collapsing within months. The National Bureau of Economic
Research dates the resulting downturn from January 1920 to July 1921, one of
the shortest but steepest contractions in U.S. history, and consumer prices
followed into outright decline, falling 10.5% in 1921. Two constitutional
changes reshaped the country that year, too. The 18th Amendment’s ban on
alcohol took legal effect January 17, enforced under the Volstead Act
Congress had passed the previous October. Then, on August 18, Tennessee’s
ratification of the 19th Amendment secured women’s right to vote nationwide,
and women cast ballots in a presidential election for the first time that
November, when Warren Harding won on a promise to return the country to
“normalcy” after a decade of war, pandemic, and rising prices. First-class
postage held at 2 cents, unchanged since mid-1919.
MLA: “Inflation from 1918 to 1920: $100 is worth $132 today.” InflationCalculator.com, U.S. Bureau of Labor Statistics CPI-U data, https://inflationcalculator.com/inflation/1918-to-1920/
APA: InflationCalculator.com. Inflation from 1918 to 1920. Based on U.S. Bureau of Labor Statistics CPI-U data. Retrieved from https://inflationcalculator.com/inflation/1918-to-1920/