The state's jobless rate dropped three-tenths of a point in January for the month before.
The 8.7 percent unemployment rate announced by the Department of Administration is the same rate officials had said was the figure for December. But since that time, the statistics have been through an annual benchmarking revision. So, as of now, the official state rate for December is not 8.7 percent but 9 percent. Aruna Murthy, the agency's director of economic analysis, said such adjustments are inevitable.
"It's all a sample-driven methodology," said Murthy. "You do take samples in the state and the sample size is not really large. We have to look at the sample and, given that we are trying to do all the numbers based on samples, that's the story at that given time on how we see it. And then subsequent to that we see changes. And then we adjust that to account for the changes."
Those annual adjustments are not just to recent figures. Murthy said it now appears that Arizona's unemployment rate peaked in November 2009 at 10.8 percent. That's four-tenths of a point higher than the revised peak which was announced just a year ago. And the original November 2009 number, announced at the time, was 9.3 percent.