A Priori Voting Power Distribution under Contemporary Security Council Reform Proposals Abstract: This paper analyzes the distribution of a priori voting power of states and regional groups within the UN Security Council, under the most salient reform proposals of the past decade. The results obtained show that moderate proposals, which do not seek to expand veto rights, generally yield a higher voting power share for non-veto states in the Council (both individually and collectively), at the expense of veto states, but do not significantly alter the geographical distribution of voting power. By constrast, the more radical proposals, which seek to expand veto rights, yield a more balanced regional representation, but have the adverse effect of concentrating voting power almost entirely in the hands of the small number of states with veto rights, with non-veto states cumulatively holding less than 2% of all voting power shares in the Security Council under the Normalized Banzhaf index and less than 0.01% under the Shapley-Shubik index. Keywords: voting power indices, reform proposals, regional groups, Security Council, voting power, voting rules 1. Introduction Pre-proofed version. The published version of the paper can be found here: https://link.springer.com/article/10.1057/jird.2015.32. Volacu, Alexandru, (2015, advanced online publication), "A Priori Voting Power Distribution under Contemporary Security Council Reform Proposals", Journal of International Relations and Development, https://doi.org/10.1057/jird.2015.32.