If history is a reliable guide, the recession of 2008 is now unavoidable.

The dismal jobs report released Friday showed overall employment to be lower than it was three months ago. Every time such a slump has occurred since the early 1970s, a recession has followed  or already been under way.

And if the good times have really ended, they were never that good to begin with. Most American households are still not earning as much annually as they did in 1999, once inflation is taken into account. Since the Census Bureau began keeping records in the 1960s, a prolonged expansion has never ended without household income having set a new record.

For months, policy makers and Wall Street economists have been predicting, and hoping, that the aggressive series of interest rate cuts by the Federal Reserve would keep the economy growing, despite the housing bust. But the possibility seemed to diminish almost by the hour on Friday.

Shortly after 8 a.m., the Fed announced yet another measure meant to unlock the struggling credit markets. At 8:30, the Labor Department released the unexpectedly poor jobs report. Almost immediately, the economists at JPMorgan Chase  who only last week had told clients they thought the economy was still growing  reversed course and said a recession appeared to have started earlier this year.