ATLANTA -- Activity at Georgia's factories increased in several ways, according to a survey released Thursday by Kennesaw State University's Econometric Center.

The Purchasing Managers Index compiled from the survey rose 1.6 points in December from the previous month to 53.9. Economists believe a reading above 50 on the index predicts growth in the overall economy.

The national index stands at 57.0 after falling 0.3 points.

Among the survey components showing improvement were hiring, commodity prices and the time it takes suppliers to make deliveries. Plus, the state index has averaged above 50 points for the last three months, suggesting Georgia manufacturing is expanding, according to Don Sabbarese, director of the Econometric Center.

When the Georgia purchasing managers answering the survey were asked to estimate their plant's production levels for the next three to six months, 39 percent predicted it would be higher. But Sabbarese noted that the percentage forecasting higher production has fallen since August.