Measuring the Voting Power of Coalitions in the Islamic Parliament, the Cooperative Games Approach

The legislature is a manifestation of national sovereignty and one of the most important issues of policy and decision making in the country. Parliamentarians not only express their views on the status of the law, opinions but rather the selection of the Cabinet of Ministers and their removal, the comment declares themselves. Therefore the power of a parliamentary member is to apply his vote through voting. But how can this voting power be changed? The purpose of this paper is to measure the voting power of the members related to major political coalitions in the Islamic parliament using the theory of games. Using Shaply-Shubik's index, voting power of the three coalitions, reformist, and independent were measured in three election periods of 2007, 2011, and 2015. The results show that in the eighth period (2007-2011), all of voting power was for the principlists and the other two coalitions were dummy coalitions. In the ninth period (2011-2015), the voting power was again restored by the principlists and the other two coalitions were dummy coalitions. In the tenth period (2015-2019), despite the difference in the seats of the principlists and reformist and independent coalitions, the voting power is equally divided among all three coalitions. This is a very interesting conclusion that the number of seats in a coalition does not always reflect the strength of that coalition. It is suggested that the Islamic parliament Research Center use this approach in measuring the voting power of the fractions in the specialized parliamentary committees.