This study analyzes the competitive aspects of public-private partnerships (PPPs) under Unsolicited Proposals (USPs). USPs differ from regular PPP arrangements from the moment that projects are proposed from scratch by private entities. We rely on a mixed-method approach. First, we work on a database of 57 USPs and then develop two case studies from sanitation and highway sectors. After identifying minimal competitive levels, the analysis explores some policy reasons behind that outcome, such as lacking information and the discretionary misuse of auction design, particularly at the subnational government level.