WASHINGTON (AP) — The American economy, slowed by last fall’s 43-day government shutdown, grew at a sluggish 0.5% annual pace from October through December, the Commerce Department reported Thursday in downgrade of its previous estimate. U.S. gross domestic product— the nation’s output of g oods and services — decelerated in the fourth quarter after registering impressive growth of 4.4% from July through September. The latest number was marked down from the Commerce Department’s previous estimate of 0.7% fourth-quarter growth. Federal government spending and investment fell at a 16.6% annual pace because of the shutdown, lopping 1.16 percentage points off fourth-quarter GDP growth. ...read more read less