Friday’s job report shows that White House economist Greg Mankiw was very nearly right when he projected almost a year ago that jobs could rise by 2.6 million in 2004. Of course, he was widely ridiculed inside Washington after making this statement, and at one point even the White House turned its back on the Harvard professor’s estimate. But the Labor Department’s latest employment release shows the yearly gain for nonfarm payrolls coming in at 2.3 million. That’s close enough for government work. It’s also the best jobs performance in five years. Why so good? The labor market responded powerfully...