While employers in L.A. County added a robust 17,000 non-farm payroll jobs in March, the number of Angelenos saying they have jobs dropped by 13,000, according to figures released Friday by the state Employment Development Department.

This caused the unemployment rate to jump to 5.0 percent from 4.6 percent in February, higher than the 4.8 percent recorded in March 2006.

Much of this discrepancy might be traced to job cutbacks among independent real estate agents and the “off-the-books” workforce in the residential construction sector as the housing market continued to stall out. These jobs do not show up on employer payrolls, which would explain why payroll jobs continued to increase during the month while there was a drop in jobs in the separate household survey data.

“It certainly seems a reasonable explanation for what we’re seeing with the divergence of these numbers,” said Brad Kemp, labor market consultant with the state Employment Development Department.

This is the reverse of what was happening a couple years ago as the ranks of independent contractors and “off-the-books” workers surged and drove the unemployment rate down to record low levels while employer payrolls registered only sluggish growth.

Statewide, the unemployment rate was 4.8 percent in March, unchanged from February and down a smidgeon from 4.9 percent in March 2006. Total non-farm payrolls rose a modest 18,500 jobs, or 0.1 percent, to 15,244,300.

In L.A. County, non-farm payrolls rose to 4,124,100 in March, the highest level since the seasonal peak last December and up 37,700 from March 2006. The monthly jump was led by increases in professional and business services (up 3,100 jobs), information services (also up 3,100 jobs) and food services (up 2,600 jobs). The only sector showing a significant month-over-month decline was trade, transportation and utilities, down 1,700 jobs.

Over the past year, the big job-gaining sectors have been professional, scientific and technical services (up 9,100) and healthcare/social assistance (up 9,000).

Manufacturing continues to be the big losing sector, down 8,800 jobs over the year. However, total manufacturing employment appears to have stabilized at about 458,000 after an unexplained dip in January.