Thanks in part to greater use of technology, 1999's first calendar quarter saw increases in both productivity and output in manufacturing, while hours at work declined. Indeed, the January-March quarter was the fourth consecutive quarter in which there's been such movement, reports the U.S. Labor Dept.'s Bureau of Labor Statistics. In the first quarter of this year, productivity in manufacturing rose 5.8% on a seasonally adjusted annual basis; output rose 1.3%, and hours worked fell 4.3%. Unit labor costs in the first quarter declined at a 0.9% annual rate, the 23rd time they've fallen in the last 31 calendar quarters. Nevertheless, Stan Shipley, senior economist at Merrill Lynch & Co. Inc., New York, issues this cautionary note: "It should be expected . . . that as the economy moderates, labor productivity gains will be tempered."