This paper argues that Coase provides the primary 20th century exemplar of the grounding of analytical developments in economics in direct fieldwork observation. In particular, his focus on the business enterprise, its internal functions (including decision-making), and its external relations (including contracting) has provided a stimulus for radical developments in microeconomics and in managerial and decision economics in particular. The argument is developed by a stylization of the development of economics, referring to Adam Smith in the 18th century, Alfred Marshall in the 19th century, Ronald Coase in the 20th century, and Elinor Ostrom in the 21st century
