There is growing interest in using messaging to drive pro-social behaviors, which contribute to investment in public goods. We worked with a leading NGO in Peru to randomize nine different prorecycling messages that were crafted based on best practice, prior evidence, and theories of behavioral change. Different variants emphasized information on environmental or social benefits, social comparisons, social sanctions, authority, and/or reminders. None of the messages had significant effects on recycling behavior. However, reducing the cost of ongoing participation—by providing a recycling bin—significantly increased recycling among enrolled households.