Bob Doll: What's good for economy not so for stocks

What's good for the U.S. economy right now is not necessarily good for stocks, market watcher Bob Doll told CNBC on Friday-the last trading session in a very volatile January.

Lower oil prices and a stronger dollar are historically perceived as positives for the economy. But both trends are hurting corporate earnings in the latest quarter and therefore the stock market, Nuveen Asset Management's chief equity strategist said in a " Squawk Box " interview.

"The hit to energy and related earnings from declining oil prices is nearly immediate," he said. "The benefit to everybody else, consumers in particular, is stretched out over time." That's what is so confusing to investors, he added.

The Dow Jones Industrial Average (Dow Jones Global Indexes: .DJI) and S&P 500 (^GSPC) each would have to gain about 2 percent on Friday for the indexes to make it back to breakeven for the month, which investors watch closely because of the old adage "as January goes, so goes the year."

Coming into 2015, Doll said he had thought expectations for 8 percent to 10 percent earnings growth for the year was a tall order. "The numbers have come down a little bit in the wake of the further decline in oil prices and the rise in the dollar," he said. "They are headwinds."

But he thinks the Federal Reserve should still increase interest rates this year. "I think it's this year in part because they're starting at zero."

"We got to zero [rates] because of an emergency. The emergency, in my judgment, is long passed," he said. "They need to get rates where they belong relative to the economy, which is low but not zero."