The vast majority of large global companies consume software rather than produce it. ... If the cost of software is driven down by competition from open source, and thus a major cost of doing business is reduced for global industry, will it be a net gain or net loss to the economy?

... Economics is not a zero-sum game. Money can be spent in ways in which its positive impact on the economy is greater or lesser. If a firm spends $25 million developing a software product that never achieves widespread use and never makes much of an impact (and a huge proportion of commercial software projects fall into this category), the only positive impact on the economy will be the transfer of funds from company coffers to general circulation (and taxes) via the salaries of the employees involved.

On the other hand, if a useful piece of software becomes available at little or no cost to many companies, especially to companies that otherwise would not have been able to afford such software, it can give a major boost to that company's productivity. In that case, even if no money was spent, all those companies increased their efficiency and revenues.

— David Adams, Free Can Mean Big Money: The Open Source Economy