Part of the problem is deciding the relevant consumer of ranking information. For example, in the case of potential students law school is a human capital investment. Some combination of bar passage rate, future income, discounted to present value, and compared to tuition would do the trick for many. Presumably that would capture at least some element of scholarship and teaching effectiveness as well. The model might be refined by accounting for GPAs and LSATs of entering student in order to assess which school can do the most with the “least.” This may not be right for the public service oriented student. This calls for a ranking based on placement with public service oriented employers.
If the consumers are the public more generally (and why not since they pay the salaries of most of us) the ranking would account for the “public goods” produced by attorneys and law professors. I have no idea now to get at the first factor especially since the students tend to arrive with public or personal interest goals already in place but an indirect approach might be to assess schools by the number of graduates involved in some kind of disciplinary problem. Would it be fair to say that schools with relatively high graduate involvement in disciplinary problem are probably not emphasizing the importance of ethics and public service?
For these consumers -- the public -- scholarship only matters if it makes a difference. Counting downloads or number of articles for them is a little like the falling tree in the forest question. If you write it an no one cites it or relies on it, have you written anything at all? In this regard a ranking akin to John Doyle’s but with the focus on law schools, not reviews, would seem to make sense. Perhaps this has been done. I think it may have and would look for it but if I spend one more minute thinking and writing about rankings I sincerely hope my dean will fire me.
Finally, (don't get your hopes up, this is less than a minute) why don’t we take the law and economics approach. Let’s just ask everyone we see: Please rank the top 50 law schools. They will, in a sense, reveal their preferences no matter how ill-informed. What else matters?