Stephen Schwarzman, chief executive and co-founder of Blackstone Group, one of the world's largest and richest private equity firms, makes for an unlikely champion of the average American.

But minutes before chairing a meeting that will decide how to reward Blackstone's partners for its record profits this year, Mr Schwarzman, whose fortune Forbes has estimated at $2.5bn (£1.3bn, €1.9bn), says he is worried about the increasingly unequal distribution of wealth in the US.