Retail funds, pensions, endowments and other investors will face higher costs and lower returns if regulations requiring public disclosure of short sales are adopted, according to a study published today by the Managed Funds Association. The research, which was conducted by management consulting firm Oliver Wyman, found that short-sale disclosure regulations adopted in the United Kingdom in 2009 have caused bid-ask spreads for effected stocks to widen by more than 45%. In addition to causing higher costs for shorted stocks in the U.K., the study found that trading volume in the stocks decreased by 13%, including long trades.