But in health care markets, decisions often affect unwitting bystanders, a phenomenon that economists call an externality. The inability of health care consumers to monitor product quality leads to regulation, such as the licensing of physicians, dentists and nurses. But health care expenses can come randomly and take a big toll on a person’s finances. More people now have health insurance, but about 12 percent of adults aged 18 to 64 remain uninsured. The best way to navigate the problems of the health care marketplace is hotly debated.

Source: New York Times July 28, 2017 16:18 UTC