This document attempts to shed light on what is known, and not known, about the nature and strength of the impact of infrastructure and Public-Private Partnerships (PPPs) on economic growth, jobs, income distribution and poverty in developing countries. The concept of infrastructure has a wide range of definitions in the literature. In this document, infrastructure is defined as all the facilities used to deliver energy, transport, water and sanitation, and telecommunications. PPPs are defined as “any contractual arrangement between a public entity, or authority, and a private entity, for providing a public asset or service, in which the private party bears significant risk and management responsibility.” Following the introduction, section 1 summarizes the impact of infrastructure on growth, jobs, poverty and income distribution. Section 2 presents the results of empirical papers on the linkage between PPPs and economic outcomes, and offers a discussion of those contributions.