When the first automobiles were built in 1901, they were made by skilled workers using hand tools. Later, in 1913, Henry Ford introduced the moving assembly line, which lowered costs and speeded production. Over the years, the production line has become ever more mechanized, and today robots replace people in many tasks.

Describe the changing barriers to entry in the automobile industry and explain how the combination of market demand and economies of scale has changed the structure of the industry over the past 100 years.