While America debates higher government spending on infrastructure, governments on every continent have sold off state‐owned assets to private investors in recent decades. Airports, railroads, energy utilities, and many other assets have been privatized. Heathrow airport in London is privately owned and operated. Air‐traffic control services are fully private in Canada. In Italy and France, limited access highways are private concessions funded with toll revenue. In many areas, the U.S. is a laggard in the world on private infrastructure provision.
The issue of whether public infrastructure spending encourages economic growth has been studied extensively by economists. In the late 1980s and early 1990s, some research argued that public capital investments had double the effect of private investment on subsequent economic growth. But those findings were challenged, and the statistical techniques were found to be faulty. By the early 2000s the consensus of economists was that the effect of public investment on subsequent economic output was at best extremely low and at worst no effect at all.
The main problem with current government infrastructure spending is not its magnitude but its lack of efficiency. More roads and transit capacity may or may not make sense depending on whether the benefits exceed the costs. One sure way to find out is to have private provision and user charges. If users are not willing to pay the costs of extra or newer capacity, then calls for taxpayer involvement probably imply subsidy of some at the expense of others rather than efficiency.