WASHINGTON — The US economy, hobbled by last fall’s 43-day government shutdown, advanced at an unexpectedly sluggish 0.7% annual rate from October through December, the Commerce Department reported Friday in a big downgrade of its initial estimate. Growth in gross domestic product — the nation’s output of goods and services — was down sharply from 4.4% in last year’s third quarter and 3.8% in the second. And the fourth-quarter number was half the government’s first estimate of 1.4%; economists had expected the revision to go the other way — and show stronger growth. Federal government spending and investment, clobbered by the shutdown, plunged at a 16.7% rate, hacking 1.16 percentage points off fourth-quarter growth. For all of 2025, GDP grew 2.1%, solid but down from an initial estimate of 2.2% and from 2.8% in 2024 and 2.9% 2023.