I don't think that's a great proxy. Just because a group has high economic output and an ability to lift people out of poverty, it doesn't mean they will. The rising income inequality in the US (without a desire to increase social welfare programs) coupled with the fact that the US's economy is still growing would seem like a counterexample.

Let me try to clarify what I meant. If a culture can enhance the culture's members' ability as individuals to create higher economic output, then that culture is probably more able to lift individual members out of poverty. Or, if you prefer, it gives the individual members better tools for lifting themselves out of poverty.

I'm not claiming that it will do better at taking care of the poor. I'm claiming that poor members of that culture will be better able to help themselves.