Robert Barro makes the point that government spending isn't free

The point is that government spending doesn't produce free wealth. From the WSJ.

The overall prediction from regular economics is that an expansion of transfers, such as food stamps, decreases employment and, hence, gross domestic product (GDP). In regular economics, the central ideas involve incentives as the drivers of economic activity. Additional transfers to people with earnings below designated levels motivate less work effort by reducing the reward from working.

In addition, the financing of a transfer program requires more taxes—today or in the future in the case of deficit financing. These added levies likely further reduce work effort—in this instance by taxpayers expected to finance the transfer—and also lower investment because the return after taxes is diminished.

This result does not mean that food stamps and other transfers are necessarily bad ideas in the world of regular economics. But there is an acknowledged trade-off: Greater provision of social insurance and redistribution of income reduces the overall GDP pie.

Yet Keynesian economics argues that incentives and other forces in regular economics are overwhelmed, at least in recessions, by effects involving "aggregate demand." Recipients of food stamps use their transfers to consume more. Compared to this urge, the negative effects on consumption and investment by taxpayers are viewed as weaker in magnitude, particularly when the transfers are deficit-financed.

Thus, the aggregate demand for goods rises, and businesses respond by selling more goods and then by raising production and employment. The additional wage and profit income leads to further expansions of demand and, hence, to more production and employment. As per Mr. Vilsack, the administration believes that the cumulative effect is a multiplier around two.

If valid, this result would be truly miraculous. The recipients of food stamps get, say, $1 billion but they are not the only ones who benefit. Another $1 billion appears that can make the rest of society better off. Unlike the trade-off in regular economics, that extra $1 billion is the ultimate free lunch.

How can it be right? Where was the market failure that allowed the government to improve things just by borrowing money and giving it to people? . . .