"In conclusion, the heart of our findings is that single-blind reviewers make use of information about authors and institutions. Specifically, single-blind reviewers are more likely to bid on papers from top institutions and more likely to recommend for acceptance papers from famous authors or top institutions, compared with their double-blind counterparts."

"The primary ethical question is whether this behavior is acceptable. In one interpretation, single-blind reviewers make use of prior information that may allow them to make better overall judgments. As a consequence, however, it may be that other work is disadvantaged, in the sense that two contributions of roughly equal merit might be scored differently by single-blind reviewers, in favor of the one from a top school, while double-blind reviewers may not show this bias as strongly."

Or are you arguing that there is no ethical concern at all? The introduction seems to cover the main pro and con arguments, as part of the justification for the need for experimental evidence.