Stewart Hicks is Assistant Professor of Architecture at the University of Illinois at Chicago. He described how a simple connecting device for roof trusses helped revolutionize the home-building industry. It led to changes that worked well for the construction trades but had broad, less obvious effects. Not all have been positive.

Some facts. Denmark’s healthcare system employs around 26,200 physicians, which translates to 4.38 doctors per 1,000 residents. A figure above…