This is a thought experiment from wayyyyy back in my college days. It's not meant to scare up any kind of ideology or politics or any of that bullshit. Rather, it's a "what would you like" question:
Imagine that wealth and poverty could be measured on a scale from 0 to 10, with 0 being desperately poor (basically, having nothing) to 10 being fabulously wealthy. Now imagine that through some combination of national/societal will, custom, or circumstance, society could be arranged in a number of different ways:
There is a fairly even bell-curve distribution from 0 to 10, with the peak of the curve being at 5. This would be more or less unrestricted capitalism.
There is the same distribution, except there are no 0's or 10's. This would be capitalism, but with some social welfare programs and high taxation at the top. You don't die of hunger, for example.
There is the same distribution, except there are no 0's, 1's, or 10's. At a minimum, people have food, shelter, and medical care. This would be about where the US is now (kind of).
The bell curve slopes to the left, with a minimum of 3, an average of 6, and a maximum of about 8. This would be the social democracies of Europe, for example.
Everybody is between 4 and 6 (socialism).
Everybody is between 3 and 5 (Cuba and other true communist countries).
Everybody is 4 (various utopian and dystopian societies in literature and film).
The question is: in which configuration do you think people would be happiest? In which would YOU be the happiest?
As far as actual evidence goes, people seem to be happier overall the smaller the bell curve gets--but not TOO small. The social democracies of Europe--particularly Scandinavia.