Published in Science in 1998, Heller and Eisenberg frame their argument explicitly in terms of Hardin's classic piece of The tragedy of the commons and applied to biomedical research although it has been used and cited as relevant more broadly. They argue that just as too much open access to an expendable public resource can create a tragedy of the commons, too much ownership -- especially an intellectual domain -- can create thickets that limit the progress of science more broadly. They argue that, "privatization can solve one tragedy but cause another." Heller and Eisenberg are reacting, in large part, to the growth of patenting within in biomedical science (see Murray (2006) for more detail on case study of this in the area of mouse-research). Their core argument is that the anticommons emerges when the rights necessary to practice research are split up among a large number, and a large variety, of different researchers. This essentially introduces a set of complex collective action problems beyond those introduced by patent licensing which they suggest may create an important barrier to scientific progress. They explain quite clearly that, "the tragedy of the anticommons refers to the more complex obstacles that arise when a user needs access to multiple patented inputs to create a single useful output." They use examples of patents on concurrent fragments which they suggest may be creating thickets and reach-through licensing agreements to make this point. They end by describing why different types of organizations (i.e., non-profits and for-profits) create heterogeneous interests among rights holders, transaction costs around bundling, and cognitive biases where scientists think too highly off their own work might prevent institutional solutions to the anticommons that might reduce costs (e.g., ASCAP in the area the copyright). Theoretical and practical relevance: Heller and Eisenberg's article has been cited more than 1,300 times in the last 12 years and has become a major article in the literature critical of patents in science. The metaphor of the anticommons has become a frequently cited in the areas of open innovation, arguments in favor of open science, and critiques of the patent system more generally. That said, the article seems to be somewhat missued by a number of "downstream" academics citing it. The article is often treated as argument against particular patents. In fact, it's argument is carefully crouched in terms of the problems of patents in aggregate. In that sense, Murray and Stern's article econometric article testing the hypothesis is a somewhat rough match for the theory offered. The article was also tested by Walsh et al. (2005) who found no evidence of an anticommons effect.