Many studies have focused on the insurance industry in the US and other developed countries. Few studies have investigated the efficiency and organizational form in developing countries. This is particularly true for the Takaful insurance industry. Takaful insurance is mutual insurance based on Islamic principles. The rapid growth of Takaful insurers in many countries around the world and their long existence make it important to examine them. Chapter 1 discusses the history and the practice of insurance during the time of ancient Arabs tribes. I discuss the conduct of the Holy Prophet (SAW) relating to insurance practice. I also briefly outlines the development of Islamic insurance in the fourteenth to the seventh centuries, nineteenth century, and the development in the twentieth century. Chapter 2 investigates economies of scope and agency problems for Takaful insurance companies operating in 19 countries. I test the conglomeration hypothesis, which holds that firms can optimize by diversifying across businesses, versus the strategic focus hypothesis, which holds that firms improve by focusing on core businesses. More specifically, I analyze whether it is advantageous for insurers to offer both property-liability insurance and family insurance (life insurance), or to specialize in one major industry segment. I also test for agency problems, which imply that firms must motivate the agent to ensure compliance with the principal's wealth maximization objectives. That is, I analyze whether it is advantageous for insurers to operate under a Mudharaba (profit sharing) model or operate under a Wakala (fee based) model. I estimate cost efficiency utilizing data envelopment analysis (DEA). Then, I test for scope economies and agency problems by regressing efficiency scores on control variables and indicators for strategic focus and the operating model. The results show that the Wakala operating model is cost inefficient and focused Takaful insurers are associated with higher cost efficiency. Chapter 3 investigates the relationship between insolvency risk and efficiency for Takaful insurers. I measure the insolvency risk by computing the z-score which measure distance to default. I calculate the efficiency scores using Data Envelopment Analysis (DEA). I find that efficient firms have a higher distance to default. I also find that firms which operate in multiple lines are penalized for diversification by being more likely to become insolvent. In addition, I show that investing in sukkuk and real-estate increase the insolvency risk. Chapter 4 analyzes the coexistence of Takaful and conventional insurance. I analyze the efficiency of different organizational forms in 13 countries. Technical, allocative, cost, and revenue frontiers were estimated using data envelopment analysis. I test the expense preference hypothesis and efficient structure hypothesis. I find evidence for the efficient structure hypothesis which claims that the two organizational forms serve different market segments due to differences in managerial discretion and access to capital. I also find evidence for the expense preference hypothesis which states that mutual insurers are less cost efficient than stock insurers due to unresolved agency conflicts (e.g., higher bonus consumption by mutual managers). The results provide insight into the competitiveness of conventional and Takaful insurers from different countries. Finally, chapter 5 concludes the main results of the study. / Business Administration/Risk Management and Insurance