Yes, every human should have equal rights and access to resources. By shrinking inequality opportunities are being made more readily available to those in the working and middle class; the driving force behind our economy. In my opinion equality encourages individuals to be more a part of the economic recovery process.
I believe decreasing inequality with help the economy grow, but not a significant amount. Political inequality I feel is the main issue that needs to addressed in helping the economy grow. The political end has allowed corporations to shape the laws to how they see them fit to help their own financial gains. The only other issue with inequality I see that would bring a significant change to the economy is fixing the tax brackets, which we all know is never going to be perfect.
Better education, fair labor practices, progressive tax policy, better and public health are all things that improve when economic inequality is shrunk. All of these things contribute to economic growth in the long term. It is difficult to measure how much, since many of these factors bear out over years and decades, rather than fiscal quarters.
You really can't draw a direct line between the two. Could it? Sure. However, it isn't assured that leveling the playing field will directly lead to an improve economy. I suppose it's more likely than it is not and it's certainly something I'm in favor of, but drastically turning an economy around isn't as simple as changing one thing, even when it's something so massive.