(CNN) — The actual inflation numbers aren’t good for President Donald Trump and his party. So Trump has come up with something of a solution: just use fake inflation numbers.
Trump has been lying about inflation throughout the midterm election campaign. Among other things, he has falsely declared he has “already stopped the inflation” (it accelerated again in September), that “prices are now coming way down” (they have continued rising), and that prices are now “way down” from when former president Joe Biden left office in January 2025 (they are up 5.4% on average).
But in a series of rally speeches and comments to the press this week, Trump has gone a step further – deploying specific but phony numbers to make inflation seem better than it is.
In a Tuesday rally speech in Alaska, Trump claimed that there was just “1.7 inflation in the last three months. Think of that, 1.7. He (Biden) had real inflation; he had real inflation of 19%.” On Wednesday, more than 12 hours after newly released Consumer Price Index figures showed a 3.7% year-over-year inflation rate in September, Trump repeated in a rally speech in Montana: “We inherited the worst inflation in history, think of it, and now, the last three months, we have 1.7 – we have it down to – he (Biden) had 19%, his real number’s 19%.”
Trump’s figures are so bewildering that it is hard to figure out what exactly he is even talking about. The White House has so far ignored our requests for an explanation.
But we can think of three possible things Trump could conceivably be doing here and none of them would make his claims accurate. Heather Long, chief economist for Navy Federal Credit Union, said Thursday that “the 1.7% inflation figure is not supported by the data.”
Possibility #1: Trump is simply lying about year-over-year inflation rates
For years, Trump has invented fictional economic numbers that work better for his purposes than the actual economic numbers. So it’s very possible he’s just lying about the year-over-year inflation rates that tend to be the most commonly discussed – wildly exaggerating the highest rate under Biden and significantly reducing the most recent rates this year.
In the last three months of 2026 for which Consumer Price Index (CPI) data is available, the year-over-year inflation rate was far higher than “1.7%”: 3.7% in September, 3.4% in August and 3.4% in July. September data isn’t yet available for the Personal Consumption Expenditures (PCE) price index, but that index shows the year-over-year rate was 3.4% in August, 3.4% in July and 3.5% in June.
This wouldn’t be the first time he has made a false claim about having “1.7%” inflation for three months. In May, he falsely claimed that “just before the war” with Iran, “for the last three months, inflation was at 1.7%.” That was wrong, too, and the White House could not offer any substantiation at the time.
Peak year-over-year inflation under Biden was 9.1%, in June 2022, not “19%.” So why do we suspect that Trump might be (incorrectly) referring to peak Biden-era inflation when he claims Biden was at “19%”? In a 2022 speech, Trump said Biden and Democrats had given the country 9.1% inflation, then quickly added, “It’s not 9.1%. I believe it’s double that.”
It’s not. The Consumer Price Index has its flaws and limitations, but there is no basis for any claim that the “real” figure is double the actual CPI figure.
Possibility #2: Trump is making a highly dishonest comparison of cumulative inflation
Cumulative inflation is the total increase in prices over a given period. There has been a 1.1% cumulative increase over the last three months, according to the CPI. That’s not a “1.7%” increase, so cumulative inflation doesn’t seem like what Trump is referring to, since he almost never uses a higher number when a lower number would be more helpful to him…
…but even if he was referring to cumulative inflation, his Trump-vs.-Biden comparison would be very deceptive. That’s because there is no reasonable way to compare three-month inflation under Trump to “19%” inflation under Biden.
The total increase in prices over Biden’s four-year term as president was 21.4%, according to the CPI, so “19%” is at least in the ballpark. But it would be completely nonsensical to contrast Biden-era cumulative inflation over 48 months with Trump-era cumulative inflation over three months.
Cumulative inflation during this Trump term to date, through 20 months, is 5.4%.
Possibility #3: Trump is misstating a fair point from his adviser
This wouldn’t do anything to support Trump’s “19%” figure for Biden. But it’s possible that Trump’s “1.7%” figure for the last three months is his inaccurate rendition of a fair point National Economic Council director Kevin Hassett made this week – “core” PCE inflation, which excludes volatile food and energy prices, was at an annualized rate of 2% for the three months from June through August.
This is the most generous reading of Trump’s “1.7%” figure we can think of, but it would still mean Trump was not telling the truth. He didn’t say in any of these comments that he was referring to core inflation rather than overall inflation; during an election in which gas prices are a major driver in overall inflation and a major factor in voter discontent, that’s a big omission. And 2% is not “1.7%.”
Also, the three-month PCE rate is widely expected to increase when the September figures for that index are released later in October. After the September CPI figures were released Wednesday, three-month core CPI jumped to an annualized rate of 3.4% – rising from the previous 2% after the September data replaced the June data in the calculation.
Long said the September data “changed the trend sharply. A key reason that 3-month annualized trend looked decent in August was due to falling gas prices in June and July.” And she said that while a reference to core inflation is her “best guess” about where Trump got his number, “I still can’t come up with 1.7%” without stripping out yet more price categories.
And one more thing: Biden didn’t leave Trump the worst inflation ever
Trump has been saying at event after event that he inherited the worst inflation in US history from Biden. He didn’t, as CNN and others have repeatedly noted.
The year-over-year inflation rate was 2.9% in Biden’s last full month in office, December 2024, and 3% in January 2025, the month Trump took over partway through. Those numbers are unremarkable by historical standards, nowhere near any record, and lower than the rate every month since Trump launched a war with Iran early this year.
Trump could fairly say the 9.1% peak year-over-year inflation under Biden was the highest in more than 40 years. But even that 9.1% rate was much lower than the all-time high, 23.7%, or the highest point of Jimmy Carter’s presidency, 14.8%, which was reached in 1980. And the rate then fell significantly before Trump returned to office.
The cumulative increase in prices from the beginning of Biden’s administration to the end was also not the highest in US history; it was less than half of cumulative inflation during Carter’s term.
CNN’s Alicia Wallace contributed to this article.
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