An article, ABA J., Vol. 92, April 2006 at 54, gives a good overview of the three general methods to value intellectual property: income, market, or cost. Companies – more accurately their forensic experts – use those methods about evenly, according to a survey cited in the article for such things as acquisitions and divestiture and litigation.
One might ask whether there could be a benchmark that looks at spending on a portfolio of patents, trademarks, copyrights and other intellectual property in proportion to the value of that portfolio. Even better, one would look at a three-to-five year total investment and compare that to the current value of the portfolio (See my post of May 10, 2005 about Sarbanes-Oxley and its requirement that companies value their IP.).