Helen Pidd (Metro gold: win mayor, G2, 24 May) is right to point out that the directly elected mayor model of governance has a gender bias against female leaders. This is not just a British phenomenon. In carrying out research for my new book, Leading the Inclusive City (Policy Press), I discovered that the vast majority of directly elected mayors in the world are men.

More information: http://www.theguardian.com/politics/2016/may/31/on-mayoral-models-and-female-leaders