DrugMonkey has a conversation going about the ongoing kerfluffle over (micro)blogging of conference presentations (see also the FriendFeed discussion). I want to go off on a tangent from something that came up in his comment thread, so rather than derail it I thought I’d post here.
In his first comment in the thread, David Crotty made the following claim:

Lots of researchers support their families and labs through money generated by patents, and most universities are heavily dependent upon their patent portfolios for funding.

That doesn’t accord with my (limited!) experience — I know a few researchers who hold multiple patents, and none of them ever made any money that way — and my general impression is that the return on investment for tech transfer offices and the like is fairly dismal.
This seems like the sort of beans that beancounters everywhere should be counting, so I asked on FriendFeed whether anyone knew of any data to address the question of whether universities really make much money from patents. Christina Pikas pointed me to the Association of University Technology Managers, whose 2007 Licensing Activity Survey is now available.
I extracted data for 154 universities and 27 hospitals and research institutions. Between them, in 2007, these institutions filed 11116 patent applications, were awarded 3512 patents, and gave rise to 538 start-up companies. I calculated licensing income as a percentage of research expenditure:

Apart from New York University (I wonder what they own that’s so profitable?), it’s clear that none of these universities are “heavily dependent upon their patent portfolios for funding”. In fact, more than half of them (78/154) made less than 1% of their research expenditure back in licensing income, and the great majority (144/154) made less than 10%.
Licensing income for Massachusetts General Hospital and “City of Hope National Medical Ctr. & Beckman Research” (whoever they are) amounted to 65-70% of research expenditure, but none of the other hospitals or research institutions made more than 20%. More than half of this group (15/27) made less than 2%, and most of them (23/27) made less than 10%.
The distribution looks just about as you would expect:



I also wondered whether there was any evidence that greater numbers of patents awarded, or more money spent per patent, resulted in higher licensing income. As you can see, the answer is no (insets show the same plots with the circled outliers removed):




I don’t know how representative this dataset is; there are several thousand universities and colleges in the US, and surely even more hospitals and research institutions, so the sample size is relatively small. It does include some big names, though – Harvard, Johns Hopkins, MIT, Stanford, U of California — and I would expect a list of schools answering the AUTM survey to be weighted towards those schools with an emphasis on tech transfer.
In any case, I’m not buying David’s assertion that “most universities”, or most hospitals or research institutes for that matter, rely heavily on licensing income. And that being so, I am also somewhat skeptical about the number of researchers’ families being supported by patents.
What’s the Open Science connection? Well, if you’re interested in patenting the results of your research, there are a lot of restrictions on how you can disseminate your results. You can’t keep an Open Notebook, or upload unprotected work to a preprint server or publicly-searchable repository, or even in many cases talk about the IP-related parts of your work at conferences. It seems from the data above that most universities would not be losing much if they gave up chasing patents entirely; nor would they be risking much future income, since so few seem to get significant funds from licensing. My own feeling is that any real or potential losses would be much more than offset by the gains in opportunities for collaboration and full exploitation of research data that come with an Open approach.
Updates:
1. Christina left a comment pointing out that patents may be required for more than simply making money from licensing:

…an extremely important reason universities patent [is] to protect their work so that they may exploit it for future research… it turns out that universities have to patent in life sciences – even if they don’t actively market and license these patents – to be able to attract new research money from industry.

There are two distinct points here: first, that if you don’t patent you may not attract industry partners, and second, that if you don’t patent you may end up licensing your own tech back from someone else (I note that most tech licenses I know of are cheap or free “for research purposes” so the latter factor might not weigh so heavily). According to the 2007 AUTM data, industry investment in academic research amounted to about 7% of research expenditure and was up 15% over 2006.
2. David responded on DM’s thread with some counter evidence, on reading which I realise that the data above may (likely?) only show what the university received and not any money that went to the labs or researchers involved. Tech transfer may not be financially worth it for the university, except that it might still be doing good things for individual labs and PIs, and so would constitute a support service the university offers its research community. It also strikes me that my experience, such as it is, is mainly with Australian researchers, whereas David’s is in the US, so cultural differences may also apply.
3. More from Christina at her own place, here.
_____________
If you want the data, the spreadsheet I used is here.