1. Department of Marketing, Tilburg School of Economics and Management, 5037 AB Tilburg, Netherlands;
2. CEPR, London EC1V 0DX, United Kingdom;
3. Department of Econometrics and Operations Research, Tilburg School of Economics and Management, 5037 AB Tilburg, Netherlands;
4. Pamplin College of Business, Virginia Tech, Blacksburg, Virginia 24061