Consumption Demand

Consumption demand represents the demand for goods and services by individuals and households in the economy. This is the major category in the national income accounts for most countries, typically comprising from 50% to 70% of the GNP.

In this model, the main determinant of consumption demand is disposable income. Disposable income is all the income households have at their disposal to spend. It is defined as national income (GNP), minus taxes taken away by the government, plus transfer payments that the government pays out to people. More formally this is written as,

Yd = Y - T + TR

where Yd refers to disposable income, Y is real GNP, T is taxes and TR represents transfer payments.

http://internationalecon.com/Finance/Fch50/F50-2.php