Keynes was absolutely right. As Pat said above, the key is for the government to pay the people to build that which benefits the community. The people then have money to spend, and so the local businesses profit and grow...and all the while the people and the businesses pay taxes which refund the government for its initial investment. Of course that's a gross oversimplification, but that's the basic idea...and it works. That's why ALL first-world democracies are socialized democracies with high taxes, strong regulation, and a significant social safety net.