<P> The welfare definition of economics is an attempt by Alfred Marshall, a pioneer neoclassical economist, to redefine his field of study . This definition expands the field of economic science to a larger study of humanity . Specifically, Marshall's view is that economics studies all the actions that people take in order to achieve economic welfare . In the words of Marshall, "man earns money to get material welfare ." This is why economists since Marshall have described his definition as the welfare definition of economics . This definition enlarged the scope of economic science by emphasizing the study of wealth and humanity together, rather than wealth alone . </P> <P> In his widely read textbook, Principles of Economics, published in 1890, Marshall defines economics as follow </P>

Who defined economics as the study of mankind in the ordinary business of life