SAN FRANCISCO — Delaware isn't the first state that comes to mind when thinking of U.S. high-tech hubs, but it's the top state in innovation and competitiveness by at least one measure: the percentage of international patent applications filed.

That's the result of research released Thursday (Nov. 1) by the Kansas City-based Kauffman Foundation. The study, "U.S.-Based Global Intellectual Property Creation," which ranked state, university and corporation patent application filings in 2006 and 1998.

Delaware was followed in the per-capita rankings by Massachusetts, Minnesota, California and Connecticut.

State rankings are based on the percentages of international patent applications per 100,000 workers that are filed under the Patent Cooperation Treaty (PCT). Administered by the World Intellectual Property Organization, the treaty allows inventors use just one application to protect their IP in over 100 countries.

There's a reason for Delaware's relatively high numbers.

"The Delaware numbers are inflated because of the many companies that are incorporated there, but don't actually have their R&D facilities there," said John Rabena, a Washington-based patent attorney for the law firm Sughrue Mion.

In other states, the numbers more clearly reflect the reality of where R&D is taking place. "Most of the other states' numbers are more accurate. In California and Massachusetts, for example, the engineers are there," said Rabena, who specializes in electrical technology patents. PCT applications are more significant than those submitted to the U.S. Patent and Trademark Office (USPTO) when measuring international innovation and competitiveness, according to study lead author Vivek Wadhwa.

"In the U.S. we're always focused on USPTO filings. They're important but they have nothing to do with our global competitors," said Wadhwa, Wertheim Fellow at Harvard Law School's Labor and Worklife Program. "What's changed in the last decade is that global patents are becoming more important."

PCT applications also cost more. Rabena said the report's overall conclusions are of greatest interst. "It is one way to tell where important technological advances are coming from because the PCT applications are more expensive."

The U.S. has seen a steady increase in PCT applications since 2003 and remains the top filer worldwide. But as other countries step up their tech competitiveness, the U.S. share of those applications has decreased from 37.4 percent to 34.1 percent.

In the state-by-state comparisons, Delaware produced 82.1 patents per 100,000 workers in 2006, up from 55.6 in 1998. It was first place in national rankings in 1998 as well.

Oregon, Vermont, and North Dakota zoomed up in their rankings while Idaho and Louisiana saw sharp declines.