Influence of Proxy Advisors (like ISS/Riskmetrics)

A comment submitted in response to the SEC "proxy plumbing" concept release attaches a couple of law review articles. One of the authors states: 

As our articles note, the potential influence of proxy advisory firms is likely to increase with the adoption of new initiatives regarding shareholder voting such as say on pay, majority voting, the elimination of broker voting and, potentially, proxy access. We are concerned about the potential influence exercised by private organizations that lack an economic stake in the companies they evaluate. In particular, we are troubled by the absence of mechanisms to hold proxy advisors accountable for their recommendations. We question whether investors have adequate incentives and information to allow market forces to monitor the quality of the information provided by proxy advisors. We note that federal regulation has fostered the growth of these firms by creating a need for institutional investors to document the rationality of their voting procedures. Although our study suggests that not all institutions blindly follow the ISS recommendations, they nonetheless rely heavily on proxy advisors in making their voting decisions