Source? Reality. Look at the savings and investment rates for the poor. Where do you think the money is going? Most people still source their large purchases locally, even if it's at a store chain, which keeps the local economy going because there are plenty of services used at those stores that are local.

A guy who goes and buys a nice new luxury TV from a local Best Buy is still supporting local businesses indirectly because that Best Buy is going to have multiple contracts with local businesses for services.