A number of people — Greg Mankiw, in particular — have been pointing to relatively low new claims for unemployment insurance as a sign that the economy is actually doing just fine.

Oops.

WASHINGTON (MarketWatch) – First-time jobless claims rocketed higher last week. Initial claims rose 69,000 to 375,000 in the week ended Jan. 26, the Labor Department reported Thursday. This is the highest level since early October and the biggest gain since September 2005 in the wake of Hurricane Katrina.

Now, to be fair, this number jumps around a lot, partly because of big problems in getting the seasonal adjustment right. Probably things aren’t as bad as this latest number suggests — but probably they weren’t as good as the last few reports indicated, either.

Meanwhile, other stuff also suggests problems: