How--and Why--to Invest in the Dow

After 123 years, has the Dow Jones industrial average finally become obsolete? It pains me to think so. My fondness for the index can be traced to a book I coauthored 20 years ago called Dow 36,000, but today's Dow is not the same as the Dow of 1999. [Editor's Note: Read Knight Kiplinger's 2011 take--Dow 36,000 Revisited --on James Glassman's book, more than a decade after it was published.] More than half of the stocks have been replaced. Even so, the adjustments fail to reflect a U.S. economy dramatically changed by the internet. Where is Amazon.com (symbol AMZN, $1,870)? Where is Facebook (FB, $181)? Where is Alphabet (GOOGL, $1,086), alias Google? Not in the Dow. (Stocks I like are in bold; prices are as of June 14.)

Let's face it: The Dow has