From the moment I arrived, I asked almost everyone I encountered about McAllen’s health costs—a businessman I met at the five-gate McAllen-Miller International Airport, the desk clerks at the Embassy Suites Hotel, a police-academy cadet at McDonald’s. Most weren’t surprised to hear that McAllen was an outlier. “Just look around,” the cadet said. “People are not healthy here.” McAllen, with its high poverty rate, has an incidence of heavy drinking sixty per cent higher than the national average. And the Tex-Mex diet has contributed to a thirty-eight-per-cent obesity rate.One day, I went on rounds with Lester Dyke, a weather-beaten, ranch-owning fifty-three-year-old cardiac surgeon who grew up in Austin, did his surgical training with the Army all over the country, and settled into practice in Hidalgo County. He has not lacked for business: in the past twenty years, he has done some eight thousand heart operations, which exhausts me just thinking about it. I walked around with him as he checked in on ten or so of his patients who were recuperating at the three hospitals where he operates. It was easy to see what had landed them under his knife. They were nearly all obese or diabetic or both. Many had a family history of heart disease. Few were taking preventive measures, such as cholesterol-lowering drugs, which, studies indicate, would have obviated surgery for up to half of them.Yet public-health statistics show that cardiovascular-disease rates in the county are actually lower than average, probably because its smoking rates are quite low. Rates of asthma, H.I.V., infant mortality, cancer, and injury are lower, too. El Paso County, eight hundred miles up the border, has essentially the same demographics. Both counties have a population of roughly seven hundred thousand, similar public-health statistics, and similar percentages of non-English speakers, illegal immigrants, and the unemployed. Yet in 2006 Medicare expenditures (our best approximation of over-all spending patterns) in El Paso were $7,504 per enrollee—half as much as in McAllen. An unhealthy population couldn’t possibly be the reason that McAllen’s health-care costs are so high. (Or the reason that America’s are. We may be more obese than any other industrialized nation, but we have among the lowest rates of smoking and alcoholism, and we are in the middle of the range for cardiovascular disease and diabetes.)Was the explanation, then, that McAllen was providing unusually good health care? I took a walk through Doctors Hospital at Renaissance, in Edinburg, one of the towns in the McAllen metropolitan area, with Robert Alleyn, a Houston-trained general surgeon who had grown up here and returned home to practice. The hospital campus sprawled across two city blocks, with a series of three- and four-story stucco buildings separated by golfing-green lawns and black asphalt parking lots. He pointed out the sights—the cancer center is over here, the heart center is over there, now we’re coming to the imaging center. We went inside the surgery building. It was sleek and modern, with recessed lighting, classical music piped into the waiting areas, and nurses moving from patient to patient behind rolling black computer pods. We changed into scrubs and Alleyn took me through the sixteen operating rooms to show me the laparoscopy suite, with its flat-screen video monitors, the hybrid operating room with built-in imaging equipment, the surgical robot for minimally invasive robotic surgery.I was impressed. The place had virtually all the technology that you’d find at Harvard and Stanford and the Mayo Clinic, and, as I walked through that hospital on a dusty road in South Texas, this struck me as a remarkable thing. Rich towns get the new school buildings, fire trucks, and roads, not to mention the better teachers and police officers and civil engineers. Poor towns don’t. But that rule doesn’t hold for health care.