NEW YORK (CNNMoney.com) -- Retail sales have generally been strong this year, with retailers gearing up for what is expected to be a solid holiday season. Housing markets are grinding down.

But you can't spot those trends by counting employees in those two key sectors of the U.S. economy.

Thursday brought the latest sign of a strong retail sector, as about three out of four store chains reported better than expected September sales.

But retail employment during the past year has consistently lost ground in the government's monthly reports. Retailers have shaved more than 100,000 jobs off their payrolls - or about 50 percent more cuts than General Motors (Charts) and Ford Motor (Charts) plan to do combined as they close plants and trim staff.

Meanwhile losses in housing and real estate have been modest. Some months there have even been gains. Overall residential construction and contractors had about 70,000 more employees on payroll in August than they did a year earlier, when building was white hot, although they have trimmed about 38,000 jobs off their payrolls since hitting a high point in February.

And the real estate sector overall had about 41,000 more employees in August than it did a year earlier, and it has seen steady gains most months over the past year.

Economists aren't looking for these kinds of trends to reverse when the government reports its September jobs figures Friday.

Overall, economists surveyed by Briefing.com forecast that employers added 120,000 jobs in September, down from 128,000 added in August. Jobs gains have been between 110,000 and 134,000 each of the past five months.

The unemployment rate is forecast to stay at 4.7 percent.

The difference in jobs in the retail and housing sectors is probably best explained by the difference in the respective industries.

David Seiders, chief economist for the National Association of Home Builders, said most contractors are cutting back, but in hours worked, not the number of employees on payrolls.

"You can cut back your labor expenses a good bit without taking people off the payrolls," said Seiders. "If you've got skilled craftmen, you certainly don't want to lose them. It's not just plumbers or electricians, but even framers or a good wall board guy - these are people you don't want to lose if the market picks up again."

Similarly, many people who work for real estate firms are paid on a commission basis, so the firm isn't being squeezed by labor costs if staffing stays high in the face of softer sales.

And the record real estate sales and strong housing prices of 2005 helped bring many new people into the profession looking for a chance to cash in on the formerly white hot market. It will take an extended downturn in home sales for people to leave the field, said Walter Molony, spokesman for the National Association of Realtors.

"We had an unprecedented growth in membership to go hand and hand with growth in sales," said Molony. "There's generally about an 18-month lag after a downturn in sales until there's a downturn in membership."

Retailers are meanwhile trying to get more productivity out of the sales staff they do have working. Scott Krugman, spokesman for the National Retail Federation, said the trend of more carefully charting customer flows and adjusting staffing to more closely meet those needs has picked up quite a bit among major retail chains in the past three years, and particularly in the past 12 months.

"It's a growing trend," he said. "The analytics they have available to them now to understand customer flow and maximize schedule is phenomenal."

In addition, economists and experts say there's been a cut in retail employment association ed with the growing consolidation within the industry.

Within the past 18 months, for example, Kmart purchased Sears Roebuck to form Sears Holding (Charts); May Department Stores Company was acquired by Federated Department Stores (Charts) in August 2005; Albertson's, then the nation's No. 2 grocer, was purchased by a group that included another competitor Supervalu (Charts) and drugstore chain CVS (Charts). And No. 3 drugstore chain Rite-Aid (Charts) is in the process of buying the Brooks Eckerd drugstore chain.

Many of those mergers have led to store closings, along with consolidations within the corporate support staff.

In addition, retail employment has not recovered completely from the hit it took from massive disruptions in the Gulf Coast region from hurricanes Katrina and Rita, according to Jeoff Hall, the chief U.S. economist for Thomson Financial.

Hall said that even though retailers have reopened many of the stores that were closed after the storms, many are having trouble finding both the customers and employees they need.

Hall said another reason for the weakness over the past 12 months is that there was probably overbuilding and excess hiring before that time. "From August of 2004 to August 2005, you had a very large increase of retail employment, about 256,000 jobs or almost 12 percent of all jobs created," said Hall. "We were over-saturated in retail employment and it takes a while to burn it off."

And the real estate slump is bound to be having an indirect impact on retail employment, according to economists. "When housing activity slows, there's a sympathetic slowing on consumer spending on certain complementary items," said Joel Prakken, chairman of Macroeconomic Advisers. "There's less spent on new furniture, on appliances."

Prakken's firm's ADP National Employment Report estimates there was only a a 78,000 gain in payrolls in September. He said much of the weakness in employment is due to the brakes being put on the economy by the housing slump, even if housing employment isn't falling off sharply.

"Almost all of that (slowdown) is coming from the housing, either directly or indirect channels," he said.

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