It is important that policy makers understand the intricacies of their cities’ rental housing (both formal and informal) and know how to formulate effective, flexible policies to regulate and promote it. The first section of this guide reviews the characteristics of rental housing markets and how they function. The issues of demand and supply of rental housing are discussed, including the concept of rent-free housing. The later part of the guide presents policy options to regulate, promote and expand rental housing — especially for the urban poor