Ms. Truss has been cheered on by conservative champions of supply-side economics in the United States, including many of the chief backers of Mr. Trump’s tax cuts. Stephen Moore, who served as an outside economic adviser to the former president, praised Ms. Truss for her willingness “to challenge the reigning orthodoxy by sharply cutting taxes to boost growth,” calling the package “a gutsy and sound policy decision.”
“By far the most important change is the reduction in the top income tax rate from 45 percent to 40 percent,” Mr. Moore wrote. “This will bring jobs, capital and businesses back to the U.K.”
A host of critics, though, have lined up to denounce the tax package, warning it will provoke economic war with the Bank of England and risk a damaging combination of economic contraction and soaring prices, which could in turn hurt the global recovery.
The impact of previous tax cuts, including those signed into law by Mr. Trump in 2017, provides fodder for those critiques.
Much as Ms. Truss has proposed to do, Mr. Trump reduced tax rates for income earners across the spectrum, including those in the highest bracket. He also cut a variety of business tax rates — a contrast with the British plan, which cancels a planned increase in corporate taxes. Mr. Trump said his full package of cuts would jump-start economic activity by encouraging businesses to invest, hire and raise wages.
Yet initial evidence, which includes studies from I.M.F. economists, suggests Mr. Trump’s cuts did not deliver the steep gains in investment and productivity that conservatives had promised. If such gains came to pass in Britain, they could help counter inflation there.
Instead, the cuts increased consumer spending, an outcome that helped temporarily expand growth in the United States, the I.M.F. found, but which could be dangerous in a high-inflation environment.