The short-term economic news for Southeast Michigan was improved in December, breaking a string of three consecutive monthly declines, according to Comerica Bank's Michigan Economic Activity Index.

An increase in residential construction and the normalization of auto production after the nearly six-week United Auto Workers strike against General Motors Co. were key factors, the bank said in a news release.

The positive index components in December were nonfarm employment, housing starts, house prices, light vehicle production and hotel occupancy. Negative components were unemployment insurance claims (inverted), industrial electricity demand, total state trade and state sales tax revenue.

Uncertainty over trade issues diminished at the end of 2019 with signing of a trade deal with China and the USMCA agreement. However, the effects of the coronavirus outbreak in Asia and Europe could threaten supply chains in Michigan as and demand for Michigan exports, the release stated.

"We expect to see continued weak global trade data in 2020," Comerica said. "The Centers for Disease Control has issued a warning that it expects to see an increasing number of coronavirus cases in the U.S. This could result in a drag on U.S. consumer confidence in the months ahead, with negative implications for U.S. auto sales this spring."

The index increased in December to 117.9. December's reading is 20 points, or 20 percent, above the index cyclical low of 97.9. The index averaged 117.8 points for all of 2019, 0.8 points below the index average for 2018. November's index reading was 117.4.