David C. Brown

Dark Pool Exclusivity Matters

Recent dark pool proliferation has magnified regulatory and academic concerns about equal access and market quality implications. Some dark pools, hoping to create an environment more amenable to buy-side institutional investors, craft their rules to discourage – or even exclude – brokers, high frequency traders and order-flow-information traders. We examine the role participation constraints play in large trade execution and find that a dark pool targeting buy-side counterparties experiences less serial correlation in returns, less volume and volatility increase pre-trade, and more trade clustering within and across days. Exclusivity influences execution quality. Not all dark pools are created equal.

Using Group Contingencies with Punishment and Positive Reinforcement to Modify Aggressive Behaviors in a Head Start Classroom

An attempt was made to modify and decrease aggressive behaviors exhibited in a Head Start classroom. Treatment procedures designed to reduce classroom acts of aggression permitted analysis of whether group contingencies enhanced the effects of extrinsic reinforcement and punishment. The two main findings of the study were: (a) the modification procedures used led to a significant decline in the incidence of aggressive behaviors, and (b) grouping children who are striving for rewards contingent upon prosocial behavior was found to be a useful addition to other behavior modification techniques.