Grundy is hardly unique. It is one of many victims of globalization, technology and other economic dislocations that have wreaked havoc with small-town America. For years, most economists argued that rather than spend millions in pursuit of a new economic engine for such places, it would make more sense to help residents seek opportunities elsewhere.

But the proliferation of towns like Grundy across what used to be the nation’s industrial heartland — stymied by joblessness, awash in opioids and frustration — has prompted a new sense of alarm. At a recent conference organized by the Federal Reserve Bank of Boston, Lawrence H. Summers, once a top economic adviser to President Barack Obama, put it this way: “There is probably no issue more important for the political economy of the next 15 years, not just in the United States but around the world, than what happens in the areas that feel rightly that they are falling behind and increasingly left apart.”

Since the last industry peak, in 2012, the coal mines of Buchanan County have shed 1,000 jobs — roughly half. And they are not paying quite as well as they once did. Mikey Elswick estimates that 90 percent of his family has worked in the coal industry, including his father, his uncle and his brother-in-law. Still, he got out four years ago after Cambrian Coal bought the mine where he worked and said it would cut wages to around $20 an hour from $22.50. Luckily for him, the local exterminator was retiring and let him take over the business, including his roster of clients.