This thesis investigates the implications of information processing efficiency on decision making with respect to the ability of decision makers to process information in a rational and timely manner. In order to examine the different aspects of information efficiency with respect to decision making, three different settings were used. First, attitudes and perceptions held by individual decision makers play an important role in the information processing stage of a decision. Therefore, the first thrust of this thesis seeks to investigate the impact of demographic characteristics of decision makers (socially responsible investors (SRIs)) on their attitudes and perceptions (in relation to their corporate social responsibility (CSR) views). The results show that demographic characteristics are useful predictors of CSR views held by SRIs. This implies that companies can reduce their cost of capital by attracting the affluent members of SRIs community and increase their CSR rankings by creating diversity in their corporate boardrooms. These efforts, if undertaken by companies, can help increase share price of the respective companies. Government agencies can also encourage companies to implement CSR agendas by requiring companies to implement CSR agendas which will appeal to the specific members in the SRIs community (clientele effect). Second, the ability of decision makers to process information in a rational manner can be seriously undermined when decision makers are expected to match the different motivations underlying their own or others‟ objectives with the multiple choices which are available to them. In the second thrust of the thesis, a state contingent (UK horseracing pari-mutuel betting market) with multi-competitor choices is used to illustrate the discovery of the determinants of demand (day-of-the-week, weekend, public holiday, number of races in the same hour, field size, televised races, flat and jump races, race quality, timing of the race during the day, insider trading, track conditions, bookmakers‟ over-round and risk attitude of bettors) unique to different groups of decision makers (bettors). The results demonstrate that unique sets of determinants can be used to identify the different types of decision makers (that is, sophisticated and unsophisticated bettors). Clearly, the discovery of these unique determinants for demand can be used by the respective authorities (British Horseracing Board, Horseracing Betting Levy and Tote boards) in deciding which variables are important to influence the behavior of the respective decision makers (bettors and horseracing authorities). Third, decision makers ought to be able to arrive at a decision in a timely manner. The third thrust of this thesis attempts to investigate the speed of adjustment with respect to the arrival of new and unexpected information in understanding the financial integration process in the Asia Pacific region (APR). Using stock market capitalization as a measure of equity market size, it was also found that more advanced equity markets are more informationally efficient that those less advanced equity markets possibly due to the fact that the infrastructure which supports information flow enables information to be easily accessible by investors for decision making. The results suggest that a more integrated equity market in the APR can lead to a greater speed of adjustment with respect to information shocks. Therefore, domestic governments have a role to play in ensuring the necessary infrastructure to facilitate information flow is improved and better integrated with neighbouring equity markets. Finally, the thesis concludes that demographic characteristics play an important role in influencing the rational information processing involved in decision making by individuals. When confronted with choices, decision makers are affected by their various motivations and those who seek to capitalise on others‟ decisions need to be aware of these motivations. In addition, the infrastructure on which information flows is essential in influencing the speed at which information is processed