Baton Rouge ranked near the middle of the pack nationally in a report that measured the number of patents issued annually by metro area, despite the fact the city had the biggest percentage drop in the number of patents issued from 1990 to 2010.

The Brookings Institution study found that an average of 71 patents were issued per year in Baton Rouge from 2007 to 2011, enough to rank the Capital Region 141st out of 358 metro areas. But the number of patents issued to Baton Rouge businesses and research institutions fell by 5.3 percent from 1990 to 2010.

New Orleans had the second-biggest drop per metro area. The number of patents issued in the Crescent City fell by 2.5 percent from 1990 to 2010. New Orleans had an average of 79 patents issued per year from 2007 to 2011, enough to be ranked 127th out of 358 metro areas.

Lafayette ranked 173rd, at 48 patents, with no indication of whether its patent production was up or down.

Pete Kelleher, associate vice chancellor of the LSU Office of Intellectual Property, Commercialization & Development, said mature industries, such as petrochemical and chemical, traditionally don’t generate as many patents as fields such as electronics, pharmaceuticals and biomedical sciences.

Of the patents issued locally in 2011, Brookings said Albemarle Corp. was responsible for 21. ExxonMobil’s chemical patents accounted for 11, while the company’s research and engineering company generated 10 patents.

According to Brookings, the effect of patents on growth is roughly equal to that of having a highly educated work force.

Inventions, embodied in patents, are a major driver of long-term regional economic performance, the think tank said.

“In recent decades, patenting is associated with higher productivity growth, lower unemployment rates and the creation of more publicly traded companies,” the report said.

“A low-patenting metro area could gain $4,300 more per worker over a decade’s time if it became a high-patenting metro area,” the report said.

Most U.S. patents — 63 percent — are developed by people living in 20 metro areas, which are home to 34 percent of the U.S. population. Those metro areas are well-established technology and business hubs, such as San Jose, Calif., which topped the rankings with an average of more than 9,200 patents per year from 2007 to 2011; San Francisco; New York; and Los Angeles.

Brookings also broke down the number of patents issued to companies. IBM was the leader in a list dominated by giant technology firms, with more than 41,500 patents issued from 2007 to 2011. Microsoft was second, with just over 16,000 patents issued during the period, while Intel, Hewlett-Packard and General Electric rounded out the top five.

Adam Knapp, president and CEO of the Baton Rouge Area Chamber, said the results of the Brookings study were “predictable.”

“We always come in around the middle or even slightly below the pack in these technology reports,” he said.

Knapp said the key is for more private, industrial research and development to drive up the numbers of patents and for LSU to pursue more opportunities.

Kelleher said the total research at LSU is “very close” to the average recommended by the Association of University Technology Managers.

AUTM, which represents more than 300 colleges, research institutions and teaching hospitals, said there should be one “invention disclosure” per $2 million in research.

An invention disclosure is a preliminary stage in the patent process, which comes after research suggests something could be a useful device or product.

If it is determined that the finding in the invention disclosure has commercial applications, then a patent application is made, Kelleher said.

Advocate business writer Ted Griggs contributed to this report.