Harvard economics professor Robert Barro contends that it increased public expenditure by $600 billion while deterring $900 billion in private expenditure.
Read his Wall Street Journal article here.
I applaud Professor Barro for his calculations, but common sense tells you the same thing. Resources are limited. When government spends more, that means using more resources for things that appeal to politicians, leaving less for use by the private sector. Politicians have a well-known proclivity for spending on stuff that merely buys favor with special interest groups and creates short-term political benefits, whereas individuals and private organizations (for-profit and non-profit) stand to lose if they make wasteful, short-sighted decision. That difference in incentives explains why it must be the case that expanding the government means a lower standard of living than otherwise.