Final answer:
In Robert Levine's study of the 'Pace of life' in 31 countries, the operational definition was the time it takes a pedestrian to walk 60 feet in a downtown area.
Step-by-step explanation:
In Robert Levine's study of the 'Pace of life' in 31 countries, the operational definition was the time it takes a pedestrian to walk 60 feet in a downtown area. This measure was used to assess the pace of life in different countries and compare the speed at which pedestrians move in urban areas. By observing and timing the walking speed of pedestrians, Levine was able to gather data on the pace of life across different cultures.