We live in an era of ever-sprawling franchise and chain eateries. They continue to grow and expand. Regional favorites have become national contenders. But as they continue to crowd out the local byways and fill in the empty stalls in strip malls, they start to look less and less unique. Growing up, if you wanted a sandwich in Bellevue, you had Subway or Blimpie. Now, you can close your eyes on a certain stretch of Cornhusker Road and point and you’d have selected one of a dozen franchisees.

The share of doctors who belong to unions is rising quickly at a time when organized labor is losing ground with other professions. The Conversation U.S. asked Patrick Aguilar, a Washington University in St. Louis pulmonologist and management professor, to explain why the number of physicians joining unions is growing – a trend that appears likely to continue.