Republican presidential candidate Jeb Bush has been mocked by many economists for suggesting that he can lead the economy to 4 percent growth, but two prominent GOP economists think he's on to something.

The economists are Glenn Hubbard, dean of Columbia Business School and former chairman of President George W. Bush's Council of Economic Advisers, and Kevin Warsh, a former Federal Reserve governor, who now teaches at Stanford.

GDP has expanded only 2.2 percent annualized since the Great Recession ended in June 2009, the worst post-recession recovery since World War II.

"Americans need not be resigned to such a dim fate," Hubbard and Warsh write in The Wall Street Journal. "A clarion call for faster economic growth — even 4 percent, as Jeb Bush recently said — is a worthy and viable aspiration."

So how do we get from here to there? Better macroeconomic policy, they argue. That means tax reform and regulatory reform for starters. Strong free-trade and education policies also are a must, Hubbard and Warsh say.

Elsewhere on the economic front, many analysts have expressed enthusiasm about the labor market since the government reported earlier this month that more job openings exist than ever before.

But hold on to your hat, says Washington Post columnist Catherine Rampell. Why are there so many jobs openings? "Because many companies are acting like big teases," she writes.

"They say they want to hire, then drag their feet. In fact, the average time required to fill a job opening has also just reached an all-time high: 27.3 days." That's up about 50 percent over the past six years.

Steven Davis, an economist at the University of Chicago, offers two possible explanations for the long duration of vacancies.

"One is that innovations in the recruiting process, such as the use of LinkedIn, have made it easier for employers to locate workers who already have jobs and are not actively seeking new positions," Rampell writes.

Second, employment law has changed, Davis says. Some states have curbed companies' ability to dump workers at will, for example.

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