Where did the O'Brien shift come from?

The O'Brien shift, a concept in economics, originates from the work of economist John O'Brien in the early 20th century. It describes a phenomenon where shifts in consumer preferences or external market factors lead to changes in demand for certain goods or services. This shift highlights the dynamic nature of markets and how consumer behavior can influence economic outcomes. O'Brien's analysis has been influential in understanding market fluctuations and consumer trends.