I am dubious but traditional wisdom shows that the U.S. economy is getting healthier finally. I know that because Deere & Co. last week reported a quarterly profit increase of 68 percent, helped by a 29 percent gain in sales of construction equipment. This was about a month after Caterpillar Inc., the biggest maker of earthmoving equipment, said its most recent quarterly earnings had doubled.

Anyone who was taught history in school has learned that when the construction equipment business takes off in this fashion after a recession, the economy finally is moving into high gear.

By keeping up with the past, we also know that the biggest gain in retail sales in four months in July and a 15 percent profit gain by Wal-Mart Inc., the world's biggest retailer, are good signs. Americans clearly have money to spend and consumer spending accounts for about two-thirds of the U.S. economy.

Interest rates are rising too -- another classic indicator of good times. Demand for money is increasing and lenders are exacting higher rates even though the Federal Reserve is keeping short-term interest rates low, trying to assure economic growth.  

The big question to ask in the coming months is whether this economy can build back jobs.   The consumer has to pick up this ball and run with it but unemployment and higher interest rates could tackle this rally.