We apply and extend the cost-based approach to bundling and tying under competition developed in Evans and Salinger (2004) to over-the-counter pain relievers and cold medicines. We document that consumers pay much less for tablets with multiple ingredients than they would if they bought tablets...

Teachers, like all professionals, require ongoing professional development opportunities to improve their skills. This paper provides evidence on effective professional development characteristics and how at-scale programs incorporate those characteristics. The authors propose a standard set of...