The neoclassical growth modelprovides an account of how distribution of income between capital and labor are determined in competitive markets at the macroeconomiclevel over time with technologicalchangeand changes in the size of the capital stock and labor force.More recent developments of the distinction between human capitaland physical capitaland between social capitaland personal capital have deepened analysis of distribution.Consumption (economics)Consumptionis a common concept in economics, and gives rise to derived concepts such as consumer debt. Generally, consumption is defined in part by comparison to production. But the precise definition can vary because different schools of economists define productionquite differently. According to mainstream economists, only the final purchase of goodsand servicesby individuals constitutes consumption, while other types of expenditure — in particular, fixed investment, intermediate consumptionand government spending — are placed in separate categories. See consumer choice. Other economists define consumption much more broadly, as the aggregate of all economic activity that does not entail the design, production and marketingof goods and services(e.g. the selection, adoption, use, disposal and recycling of goods and services).Likewise, consumption can be measured by a variety of different ways such as energyin energyeconomicsmetrics. The total consumer spendingin an economy is generally calculated using the consumption function, a metric devised by John Maynard Keynes, which simply expresses consumption as a function of the aggregate disposable income. This metric essentially defines consumption as the part of disposable income that does not go into saving. But disposable income in turn can be defined in a number of ways - e.g. to include borrowed funds or expenditures from savings. Consumption also decreases demand.