The effective number of political parties (ENP) in a single member plurality rule electoral system is analyzed as a dynamic process whereby the tournament nature of the election contest induces excessive entry and sunk entry costs promote persistence even as Duverger-Demsetz type political...

2015 first using an auto-regressive distributed lag (ARDL) model and then allowing for asymmetric adjustment by adapting NARDL panel estimation techniques. After finding evidence of asymmetry at the party level, the NARDL results uncover two new stylized facts for ENP at the national party...