April 9, 2009
Work by myself (columbia and nyse) and marco avellaneda at nyu has shown that restrictions on short-selling have many adverse consequences, among them: increased volatility, big crashes, bubbles and obscured company health. I have spoken many times about this over the last year and some of my talks can be found online. Also, our work will be published in several upcoming papers in RISK and J Quant Finance.
Since you are asking for commentary I would be pleased to discuss these works at length.