Bill Gates' Last Day At Microsoft

Today is Bill Gates' last day as a full-time employee of Microsoft. After 33 years at the company, the one-time richest man in the world will be retiring at 52 to spend more time guiding the charitable Bill and Melinda Gates Foundation.

Sure, there are the blockbuster Microsoft products, like Windows and Office, used in offices and homes, everywhere, every day. But beyond that, Gates, and his company, founded 33 years ago, have fundamentally shaped how people think about competition in many industries where technology plays a central role, the behavior of modern markets, and even antitrust.

In a sense, Bill Gates can be seen as the foremost applied economist of the second half of the 20th century.

Yet the old rules of competition, so lucratively mastered by Microsoft, are being altered by the current wave of Internet computing - and Google is the company at the forefront. So far, Microsoft is struggling to adjust, and it will be up to Gates's successors to overcome the challenge or watch Microsoft's wealth and leadership in the industry steadily erode.

Whatever the future for Microsoft, the Gates legacy is impressive. The main reason that there are more than a billion copies of the Windows operating system on personal computers around the world, according to industry experts and economists, is that Gates grasped and deployed two related concepts on a scale no one ever did in the past - "network effects" and the creation of a technology "platform."