Transparency can keep health care competitive.

Health-care reformers who want a public health-insurance option to keep private health insurers competitive have a point: If there were ferocious competition in the private health-insurance markets, prices would be better controlled. In Switzerland, for example, competition among that country’s 85 private health insurers resulted in negative price increases since 2005 and considerable public support. In the U.S., by contrast, health-insurance prices rose by 16.5 percent and Americans hold insurers in low regard.