• This definition was given by Adam Smith.
• He is also known as the ‘father of economics.
• According to this definition, economics is a science of the study of wealth only.
• It deals with production, distribution, and consumption.
• This wealth-centred definition deals with the causes behind the creation of wealth.

• This definition was put forward by Alfred Marshall.
• According to Alfred Marshall, economics is the study of man in the ordinary business of life.
• It examines how a person gets his income and how he invests it.
• Thus, on one side, it is a study of wealth.
• On the other most important side, it is a study of well-being (welfare).

According to him, economics is a science that studies human behaviour as a relationship between end and scarce means that have alternative uses.

Features:

• The wants of a human are unlimited.
• It has an alternative use of scarce resources.
• It is an efficient use of resources.
• It is needed for optimisation, i.e., best allocation of resources.

According to him, “economics is the study of how people and society choose, with or without the use of money, to employ scarce productive resources which could have alternative uses, to produce various commodities over time and distribute them for consumption now and in the future among various persons and groups of society”.

It analyses the costs and benefits of improving patterns of resource allocation.

This definition is the combination of welfare and scarcity definition.