After a couple of years when things turned upside down and the District created jobs faster than Maryland and Virginia, things are back to normal.

These days it is Virginia that leads the pack again, with 2.7 percent more jobs in June than a year ago, according to the Labor Department. Maryland is in the middle with 1.7 percent and the District is the laggard at 0.8 percent.

Virginia is leading, as it has for most of the past two decades, thanks in large part to one industry: Business and professional services. The number of jobs in this category, which includes consultants, lawyers and computer programmers, is growing fast in Virginia -- a whopping 6.1 percent over the past year. In the District it was 3 percent; in Maryland, 2.5 percent. Usually local industries add or cut jobs in concert. That is, if construction companies in Virginia are adding to their staffs, so are construction companies in the District and Maryland.

But sometimes, industries on different sides of the Potomac can get out of synch, as has happened in the case of professional services. The reasons for this shed light on the economies of the three jurisdictions.

The gap probably results from the preponderance of government technology contractors in Northern Virginia, which goes a long way toward explaining why Virginia is adding these kinds of jobs faster than its neighbors. Professional service firms in Virginia are more closely tied to fast-growing defense and intelligence work, with the Pentagon and CIA headquarters both in the Commonwealth, whereas Maryland and the District rely more on lawyers and business consultants.

-- Neil Irwin