Consumption is the value of goods and services bought by people. Individual buying acts are aggregated over time and space.
Consumption is normally the largest GDP component. Many persons judge the economic performance of their country mainly in terms of consumption level and dynamics.
First, consumption may be divided according to the durability of the purchased objects. In this vein, a broad classification separates durable goods (as cars and television sets) from non-durable goods (as food) and from services (as restaurant expenditure). These three categories often show different paths of growth.
Second, consumption is divided according to the needs it satisfies. A commonly used classification identifies ten chapters of expenditure:
People in different position in respect to income have systematically different structures of consumption. The rich spend more for each chapter in absolute terms, but they spend a lower percentage in income for food and other basic needs. The percentage values of an aggregation over all the households in a country can thus be used for judging income distribution and the development level of the society.
The rich have both higher levels of consumption and savings. In differentiated product markets, the rich can usually buy better goods than the poor. This happens also because they tend to use different decision making rules. In certain conditions, the poor can pay more than the rich to satisfy the same need. In other words, consumption depends on social groups and their behaviours, as well as their proneness to advertising.
Third, one should distinguish "consumption" as use of goods and services from "consumption expenditure" as buying acts. For durable goods this difference is very relevant, since they are used for long time periods.
In this vein, the rich have a much wider cumulative bundle of durable goods purchased over time, so they enjoy a very significantly higher degree of need satisfaction, whereas the poor can suffer deficiencies even in the most basic goods.
Conversely, purchased non-durable goods that are not consumed before the deadline are a typical waste (and squander).
Fourth, only newly produced goods enter into the definition of consumption, wheareas the purchase of, say, an old house is not considered consumption in macroeconomics, since it was already counted in the GDP of the year in which it was built. Needless to say, for the consumer, both old and new goods provides some need satisfaction.
In microeconomic terms, total consumption expenditure of one household is the sum, over a span of time and across all categories, of the value (i.e. price times quantity) of all varieties of goods and services purchased, where the quantity purchased depends on the consumption average dose times the number of consumption occasions (i.e. seized consumption opportunities). Macroeconomic consumption is the sum of the consumption of all households, keeping into account that households are not independent from each other but rather communicate and co-variate.
Current income level and dynamics is the most relevant determinant of consumption. Income comes from labour (employment and wages), capital (e.g. profits leading to dividends, rents, etc.), remittances from abroad. Income from consumer's cumulative bundle (including dividends and interests on wealth) provides an additional flow to available income.
Cumulated savings in the past can be squeezed in case of necessity and give rise to a jump in consumption, similarly with what happens with wealth increase, due for instance to stock exchange boom or house prices boom. Family debt can be boosted to fund consumption, while repayments brake its dynamics.
Expectations on future income, especially if concerning short-term credible events, may also play an important role.
At household level, there are many possible rules set to control monthly, weekly or even daily consumption expenditure, resulting from empirical and theoretical approaches to consumers. These routines relate not only to income but also to the following factors among others:
general lifestyles, in particular attitudes toward savings
or consumption and shopping as "values" in itself;
According to age of the decision-maker, individual and household consumption varies, both in values and composition. Thus, aggregate consumption may be influenced by demographic factors, such as an older and older population, even though one should not rely too much on these relationships since demographic variables are extremely slow in changes, whereas consumption clearly reacts to economic climate.
A GDP component as it is, consumption has an immediate impact on it. An increase of consumption raises GDP by the same amount, other things equal. Moreover, since current income (GDP) is an important determinant of consumption, the increase of income will be followed by a further rise in consumption: a positive feedback loop has been triggered between consumption and income.
An autonomous increase of consumption, if at the same level of income, would reduce savings, but the positive loop just described (known as the "Keynesian multiplier") will imply an increase of income level with a positive impact on future savings.
If directed to goods and services produced abroad, an increase of consumption will immediately push up imports, while a similar indirect effect will result from consuming domestic products requiring foreign raw materials, energy, semi-manufactured goods.
Since usually the States separately tax consumption (say with a VAT tax), an increase of consumption will also boost this type of State revenue, as well as import duties revenue in the case of imported goods. The growth mechanism of consumption-income will also provide State revenue through income taxes.
To the extent firms decide to invest by forecasting future demand and by comparing it with present production capacity, an increase of consumption may induce new investment. In particular:
soaring consumption raises the production capacity utilization, with positive
effects on profits;
If exports are a second-best solution for domestic firm, an increase of domestic consumption might decrease export, since at the same level of production firms would prefer to sell inside the country. To verify this by yourself, try and play "You are an exporter".
Consumer dissatisfaction with current products can lead to faster adoption of new products, thus intertwining the whole new product development cycle.
An increased total market demand may induce firms to increase prices, the more so when they operate at full production capacity or they operate on monopolized markets. Thus increased price level and accelerated inflation can be an effect of booming consumption.
Consumption can lead to CO2 emissions in the atmosphere, thus contributing to climate change.
In Western countries, consumption has always grown in the last 50 years, except in few deep recessions. Its growth is smoother than investment's rise or net exports' growth. In particular, services have always systematically grown at a fairly steady pace, non-durables have often mirrored the business cycle and durables have often over-shot the fluctuations in GDP.
Sustainable lifestyles, based on satisfaction of basic needs, green consumer goods, dematerialisation, and carbon footprint off-setting, will be more and more relevant in the future.
As the main component of GDP, it is pro-cyclical almost by definition: any large fall in consumption would reduce GDP. Consumption has a smoother dynamics than GDP. During a recovery, it sustains and stabilises the trend. Durable goods, however, are strongly pro-cyclical and they may peak shortly before GDP.
Particular tax reductions and subsidies can be directed to temporarily sustain sales in order to promote extraordinary purchases. If large enough, they may help in economic turn-around from recession to recovery. Cars and house-related large expenditures have been often targeted, with green goods possibly engendering further benefits to climate change mitigation.
Food products prices in 198 countries
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