Amazon has announced that it - along with Warren Buffett's Berkshire Hathaway and the banking behemoth JPMorgan Chase - will be entering the dominion of health care. Word that Amazon was entering health care immediately depressed the value of old-school health-insurance companies. Anyone who has been a customer of either knows why. The U.S. health care system is the antithesis of Silicon Valley. Grossly inefficient and user-unfriendly, it may be the least transparent enterprise outside the Kremlin - and just as awash in money. The $3.3 trillion that Americans spent on health care in 2016 was close to Germany's entire GDP that year. It accounted for an astounding 18% of the U.S. gross domestic product - twice the share other developed countries typically spend on health - and produced a return on investment that would get any CEO fired. Life expectancy in the U.S. is actually going down. David Cutler, a health economist at Harvard, made the striking calculation that administration accounts for about a quarter of the cost of health care. He once pointed out that Duke University Hospital had 900 beds and 1,300 billing clerks. If the triad of Amazon, Berkshire Hathaway and JPMorgan Chase can find a way to bring sense to health care, the savings will accrue first for those three companies, which are not acting out of altruism. But ... when the worker reaches a doctor without having to run a gauntlet, the vaunted, disruptive efficiency of tech will have produced a common good.