Between 1918 and 1921, the Consumer Price Index went from 15.1 to 17.9.
Cumulatively, prices increased 18.5%, which works out to an average of
5.83% per year. Put differently, a dollar in 1918 bought what
$0.84 buys in 1921.
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 1921, by category:
Category
Avg. yearly inflation
$100 in 1918 →
All items (CPI-U)
5.83%
$119
Apparel
6.74%
$122
Food
-1.62%
$95.21
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–).
Consumer prices fell 10.5% in 1921, the mirror image of the wartime
inflation that had more than doubled the cost of living between
1913 and 1920. The Depression of 1920-21, one
of the sharpest contractions in U.S. history, bottomed out that July
according to the National Bureau of Economic Research, even though it had
lasted barely eighteen months. Unemployment climbed toward one worker in ten
as businesses cut production and prices to work through wartime inventories,
but the same collapse in prices also meant the recovery, once it started,
had room to run without reigniting inflation. Warren Harding took office
March 4, promising a return to “normalcy” after a decade of war, pandemic,
labor unrest, and rapid price swings; his administration moved quickly to
cut top income tax rates and federal spending. Congress also acted on
immigration that year: the Emergency Quota Act, signed May 19, capped annual
arrivals from each country at 3% of that nationality’s population in the
1910 census, the first time the United States had set a numerical ceiling on
immigration. The law favored northern and western Europe and cut total
immigration by more than half compared with prewar levels; Congress
tightened the formula again in 1924. First-class postage held at 2 cents,
unchanged since mid-1919.
MLA: “Inflation from 1918 to 1921: $100 is worth $119 today.” InflationCalculator.com, U.S. Bureau of Labor Statistics CPI-U data, https://inflationcalculator.com/inflation/1918-to-1921/
APA: InflationCalculator.com. Inflation from 1918 to 1921. Based on U.S. Bureau of Labor Statistics CPI-U data. Retrieved from https://inflationcalculator.com/inflation/1918-to-1921/