Villanova law professor Michael Risch is publishing a new paper based upon his two-year study of patent trolls (focused upon the ten most litigious trolls).  Here are some of the highlights:

• Only 8% of asserted patents included business method claims.
• Software and business method patents combined only made up 31% of asserted patents.  Those percentages seem low.
• About 17% of asserted patents came from defunct companies. 
• Another 17% were assigned directly to trolls.  This may be a sign of an industry trend – more sophisticated trolls cutting out the middleman and securing their patents directly, without any effort by anyone to commercialize the patents at all.
• The average time between patent issuance and filing of a complaint was more than 8.5 years.  My experience would have suggested a slightly lower average time, about 4-6 years.

While Risch’s statistics are interesting, I am especially interested to see the next phase of his research, investigating litigation outcomes of patent troll cases.  That analysis could be far more valuable in helping to predict case outcomes based upon a particular troll or objective characteristics of the troll’s asserted patents.