DETROIT—Comerica Bank’s Michigan Economic Activity Index rose 1 percent in February to a level of 104.0, from 102.9 in January. Economic activity in the year 2012 is equal to 100 on the index.

The index is comprised of nine variables—nonfarm payroll employment, continuing claims for unemployment insurance, housing starts, house price index, industrial electricity sales, auto assemblies, total trade, hotel occupancy and sales tax revenue.

All data are seasonally adjusted, converted to constant dollar values, and expressed as a three-month moving average.

Comerica officials said they had made adjustments to components of the index starting this month, including their relative weighting, to better reflect actual state-level GDP.

In February, six of the index’s nine components were positive: nonfarm payrolls, unemployment insurance claims, house prices, industrial electricity demand, hotel occupancy and sales tax revenue. The three components retreating in February were housing starts, light vehicle production and total state trade.

Comerica officials said they expect Michigan to continue to benefit from the rapidly reflating U.S. economy this spring. However, the auto industry, along with other manufacturing and construction industries, is being held in check by supply chain constraints, including a global shortage of computer chips. Several assembly plants in Michigan have temporarily shut down this spring and/or have throttled back production. Chip manufacturers are ramping up production. Computer chips are expected to remain in tight supply through the summer and possibly later. Payroll employment gains in March were subdued as the manufacturing sector gave up some jobs.