By Bob Baur, Ph.D., Chief Global Economist, Principal Global Investors
It's been said that economists only use decimal points to show they have a sense of humor. By that idea, the Dow already hit 20,000 on January 6th, when the high tick of the day was 19,999.63, just a few tenths off. But sometimes, those even round numbers are not a problem.
The Dow Jones Industrial Average (DIA) soared right through 10,000 in 1999 with ease, even if it did fall back a few times over the next decade. Other times, though, round numbers are a kind of barrier, as 20,000 has been for a few weeks. In the distant past, the Dow first came close to 1,000 when it hit 995.14 in February 1965. It approached that number again in November 1968, surpassed it slightly for a few days in 1972, 1976, 1980, and 1981, but never had enough…