As almost a throw-away line during his news conference Wednesday, President Obama said the stimulus package he signed into law on February 17 had saved or created 100,000 to 150,000 jobs.

“The estimate,” according to an Administration official, “does not mean that employment has risen by 150,000. Rather, it means that employment is 150,000 higher than it otherwise would have been.”

The President’s comment is not insignificant as we come into a week which will be capped with the release of the Employment Situation report on the April labor market – a report expected to show the economy coughed up another 630,000 jobs and the number of people working fell again.

[Where the explanation of the President’s comment is confusing is that it mixes jobs and employment, a common error. The jobs tally comes from the Bureau of Labor Statistics’ “establishment survey” which tracks the number of jobs; employment comes from the “household survey” which tracks the number of people working. Those numbers can be different: if a person has two jobs, that individual shows up twice in the establishment survey but once in the household survey. Taken another way, if one of the jobs is eliminated, the jobs tally goes down, but employment does not.]

In coming up with the 100,000-150,000 figure, the Administration official said, “We estimated the effect of the American Recovery and Reinvestment Act (“ARRA”) on employment as of April 29, 2009 in two ways. One was to prorate the original quarterly estimates of the effect of the ARRA prepared by the Council of Economic Advisors (“CEA”) at the time of passage in a conservative way. The second was to use the data available on actual spending as of April 21, 2009 to replace the assumed spend-out rate. We then applied the same estimates of the likely impact of spending on output and employment used in the original calculations. Both methods yield similar results (suggesting that our original spending assumptions were reasonably accurate).

Since the initial CEA estimates were based on robust assumptions, the new numbers offered by the President might be described as an estimate to the second degree.

The one certainty the Administration has is how much of the $787 billion ARRA was actually spent – that is disbursed. It can’t though track how the money was used, whether to buy goods and services or hire. Even money distributed for specific projects doesn’t guarantee hiring since if a city or county starts work on a project, it doesn’t hire every worker immediately.

The tally will come in Friday and except for some number-crunchers, the specifics won’t matter. Instead economists will be looking at trends, the same trends that lead some to believe the economy has bottomed.

One of the “green shoots” is that the advance Gross Domestic Product report for the first quarter showed the economy contracted at a 6.1% annualized rate, not the 5.0% contraction expected, but also not much different than the 6.3% decline in the fourth quarter. So while the economy didn’t improve, it didn’t get worse. There were some indicators within the GDP to suggest an uptick: a lot of the decline was due to a harsh reduction in inventory. To the extent consumers resume spending, those inventories would have to be replenished. The concern with that argument is the heavy consumer spending on services which don’t require the same level of inventory re-build.

Government spending was also surprisingly weak in the first quarter and will increase in the second.

Consumers remain the challenge for economy and Friday’s report could provide a clue as to their future direction. The employment report will include data on average hourly earnings, hours worked and the number of people employed. Earnings and employment have been dropping (and hours worked fell in March to a record low). Multiplying all three elements, aggregate earnings dropped 0.7% in March but more significantly is down 2.1% since March 2008, the third month in a row of year-year decline. January 2008 was the first time aggregate earnings had dropped year-year since all the data elements were compiled.

Mark Lieberman is the senior economist for the Fox Business Network. Prior to joining FOX, he served as first vice president and manager of economic analysis and research at Washington Mutual in New York. Before that, he served as senior vice president at Dime Savings Bank of New York (which was later acquired by Washington Mutual), where he specialized in credit and risk management. He is a member of the Executive Committee of the New York Association for Business Economics. He has a degree in Economics from the Wharton School of the University of Pennsylvania.