Are these wide swings in specialists’ cash compensation plausible?

Data in InsideCounsel, Jan. 2009 at 52, covers compensation from the Thomson Hildebrandt 2008 Law Department Survey. One of the charts shows median total cash compensation from a survey population of more than 220 law departments by seven areas of legal practice (See my post of Feb. 12, 2009: cash comp by specialty.). Since I wrote about this survey’s comparable data almost two years ago (See my post of April 8, 2007: compensation for legal specialists in-house.), I decide to match the compensation levels for the four specialties that were in both reports, putting the most recent data first.

Patent litigation ($263,080 vs. $209,900, a 25.3 percent increase)

M&A ($240,050 vs. $221,500, an 8.4 percent increase)

International ($219,282 vs. $226,200, a 3.1 percent decrease)

Companywide Compliance ($211,303 vs. $215,100, a 1.8 percent decrease)

The only explanation for this bizarre fluctuation is that the law departments that took part in the first survey were significantly different from the law departments in the second survey.