Economics like other social science subjects has no specific definition. As there are many Economists, so there are many definitions of the subject-Economics. These definitions depend greatly on the perception of the definer of the Subject.
These inevitable variations in the definition of Economics arise because of the fact that the subject studies human beings and their behaviours which can never be the same. These divergent human behaviours are subject to different interpretations. To substantiate our argument that Economics has multi-farious definitions, we will quote some definitions given by those we consider as authorities in Economics.
According to Adam Smith 1776: “an inquiry into the nature and causes of the wealth of nations”.
According to John Stuart Mill 1843: “the practical science of the production and distribution of wealth”
According to Alfred Marshal 18901 “A study of mankind in the ordinary business of life”.
However, of all the definitions of Economics adduced by Economists, the one that is more widely acceptable by the generality of Economists is the one put forward by Professor (Lord) Lionel C. Robbins in 1932.
According to Professor Robbins, Economics may be defined as “a Science which studies human behaviour as a relationship between ends and scarce meanswhich have altenative uses”. The above definition is more embracing because it embodies the basic concepts of Economics and the main fundamental problems of man -wants, scarcity, choice, exchange and opportunity cost.
According to Robbins’ definition, Economics is a science, it is explained below why Economics is called a science. That Economics is a science which studies human behaviours and that makes it a social science and not natural or pure science, As social science, Economics deals mainly with the activities of man. By ends, it means human wants, desires or needs. These human wants are numerous relative to resources used in satisfying them. By scarce means, he means the limited available resources used in satisfying numerous human wants. That is to say that the resources used in satisfying human wants which he called “means” are scarce or not many relative to their demand. By alternative uses, it means that these scarce resaurces can be used for different purposes.
For instance, a piece of land can be used to build a house or for farming. That is to say that the most pressing needs have to be satisfied first leaving others that are not most pressing till the time more resources will be made available. Since human wants are unlimited and insatiable relative to the available resources, human beings have to choose the most pressing needs and leave others that are less important ‘relative to scarce resources.
This is why Economics is also known as a science that studies scarce resources. As a result of the unlimited and insatiable nature of human needs, coupled with the scarce resources used in the satisfaction of these wants human beings are faced with the problems of wants, scarcity, scale of preference, choice and opportunity cost.