The purpose of this dissertation is to provide the means for contingency planners for regional earthquake risk mitigation to systematically determine how much to spend on mitigation versus post-event reconstruction and to prioritize alternative mitigation and reconstruction options. This dissertation is organized into three chapters. The focus of chapter one is the development of a method to estimate earthquake hazard for use in regional loss estimation. The method includes formulation of a linear program that selects a small subset of earthquake scenarios from a library of such events and estimates hazard-consistent annual occurrence probabilities so that their combined effect on the region of interest approximates that described by r-year return period for all possible events. The method is reproducible, computationally tractable, and results in earthquake scenarios, which are easily understood. We apply it to the identification of earthquake scenarios for Tehran, Iran. The second chapter develops an optimization model to help highly seismically active developing countries decide: (1) How much should be spent on pre-earthquake mitigation versus waiting until after an event and paying for reconstruction or simply not rebuilding damaged buildings?; (2) Which buildings should be mitigated and how?; and (3) Which buildings should be reconstructed and how? It extends previously developed optimization models to consider the particular issues that arise in such countries. First, the model allows for the possibility that some damaged buildings will not be reconstructed immediately and keeps track of any lost building inventory. Second, it allows the set of possible mitigation alternatives to be both the upgrade of a particular structural type or a change in the structural type. Third, the model relaxes the assumption that all buildings should be reconstructed to their pre-earthquake condition. Finally, it includes as one objective minimizing the chance of an extremely high death toll in any one earthquake as well as minimizing the average annual death toll across earthquakes. This chapter incorporates the results from the first chapter into a case study analysis for Tehran, Iran The focus of the third chapter is the introduction of equity into this type of analysis.