Governments around the world are investing in technologies that allow citizens to participate in the coproduction of public services by providing monitoring and feedback, but there is little evidence about how these initiatives affect the quality of public services. We implemented a large-scale field experiment that involved organizing 50 citizen reporters in each of 100 neighborhoods across Kampala, Uganda, to provide weekly reports to the municipal government about the delivery of solid waste services via an SMS-messaging platform, resulting in 23,856 reports during the 9-month study period. Citizen reporting did not reduce informal waste accumulation as targeted, which would indicate improvements to formal services. Using our observations as participants in the development and deployment of the reporting platform and interviews with staff at the government agency receiving the citizen reports, we show how the public generated inconsistent information that did not fit existing decision-making processes. We generalize lessons from this field experiment by explaining how coproduction involving information sharing through information and communication technologies is likely to affect public services based on the alignment of citizen-produced data with the information problems managers face; the search costs of detecting public services failures; the quality of citizen-produced data; and the operating costs of citizen-reporting platforms.