An earlier IMF study (mainly about developing countries) found this:
We find that longer growth spells are robustly associated with more equality in the income distribution. For example, closing, say, half the inequality gap between Latin America and emerging Asia would, according to our central estimates, more than double the expected duration of a growth spell.
It then posed the following problem:
The immediate role for policy, however, is less clear. Increased inequality may shorten growth duration, but poorly designed efforts to lower inequality could grossly distort incentives and thereby undermine growth, hurting even the poor. There nevertheless may be some ―win-win‖ policies
Questions which the study above tried to answer.
I'm well aware of policy risks here. In my recent analysis of Argentina, a country that suffers severely from bouts of growth intersparced with terrible recessions, the latest travails of the Argentinian economy are due to a significant extent to misguided polities trying to reduce inequality, most notably the 5% of GDP that go to energy and transport subsidies (although one could even argue that these probably increase, rather than decrease inequality as they go mostly to people with high energy consumption and the poor usually do not have airco's).