Lionel Robbins defines economics as a behavioral science that examines how scarce resources with various uses are employed to achieve goals. Wolfgang J. Fellner expands the understanding of goals in economics. He does not limit consumer behavior solely to purchasing decisions but also takes into account how goods and services are produced and consumed. Decisions regarding time use are theoretically and formally analyzed based on activities. This allows for the consideration of the process utility that has been overlooked in economics.