Because a simple walk down an average street nearly anywhere in the country strongly indicates otherwise. In science, we like to imagine that we'll begrudgingly

Because a simple walk down an average street nearly anywhere in the country strongly indicates otherwise. In science, we like to imagine that we'll begrudgingly discard our theories in the face of a single contradictory fact. Economists don't even seem to pretend that's a thing they'd ever do. There are some 50-60 million people living in poverty in the US. Schools don't have books or desks. People are quite literally fighting insurance companies for their lives on a daily basis. That's quite a lot of demand out there for pretty basic things. There are staggering numbers of unemployed and underemployed people out there as well, so we're not hurting for supply-side capacity either. There's simply more profit to be made by "investing" capital in playing financial games than there is in meeting actual demand. We can quibble about whether this is a failure of capitalist theory or a failure caused by too much regulation, or probably a dozen other claims. But whatever the case, it's a pretty cut and dried case of the bleeding obvious that we're not at capacity in our economic system.