The South Isn’t Really Doing All That Badly

The Wall Street Journal says today that the South, after years of improvement, is now falling further behind the Northeast and other regions. Here’s the chart:
The Journal’s chart starts at 1890, which makes it a little hard to see that, in fact, the South’s convergence with other regions had pretty much stopped by 1980. Here’s a simpler chart that makes this clearer:
There’s not much happening here. The South had a couple of bad years in 2013-15, but aside from that its median income has puttered along for decades at about 85 percent of the level of the West and the Northeast, and it’s actually continued to gain ground on the Midwest. It hardly seems like there’s any real trend here aside from—maybe—a slow drift downward since 2000 vs. the West and Northeast.
That said, I’d be interested to find out what happened in 2013-15. That was a fairly dramatic drop and it happened in comparison to every other region—and it changes the whole character of the trendlines. However, nothing comes immediately to mind.