What is Statistics?

Statistics deals with the collection, analysis, interpretation, and presentation of numerical data. It is a branch of mathematics and is used across many disciplines — accounting, economics, management, physics, finance, psychology, and sociology among them. In this course we are concerned with data drawn from the field of Economics.

Quantitative data. Most economic data are quantitative — that is, expressed in numbers. For example, the statement that the production of rice in India increased from 39.58 million tonnes in 1974–75 to 106.5 million tonnes in 2013–14 is quantitative data.

Qualitative data. Economics also uses qualitative data, whose chief feature is that it describes attributes of a single person or a group that are important to record even though they cannot be measured in numbers. Consider gender, which classifies a person as man/woman or boy/girl. Often it is both possible and useful to state an attribute in degrees — for example, better/worse, sick/healthy/more healthy, or unskilled/skilled/highly skilled. Such qualitative information is used widely in Economics and the other social sciences, and it is collected and stored just as systematically as quantitative information (on prices, incomes, taxes paid, and so on), whether for a single person or for a group. …