Announcements of Support and Public Good Provision∗

I find that non-binding announcements of support for a public good encourage others to contribute. Others respond with contribution even though the non-binding announcements can be — and often are — made by non-contributors. In a field experiment involving over 36,000 employees at 278 workplaces, giving employees an easy way to announce support for a charity raises an additional $525 per workplace, almost 10 % of average workplace giving. In a complementary laboratory experiment, subjects donate twice as much when they observe another subject announce support for a charity. Facilitating individuals to announce support is a powerful tool to increase public good provision. C91, C93, H4