The business cycle or trade cycle i

The business cycle or trade cycle is a permanent feature of market economies: Gross Domestic Product (GDP) fluctuates as booms and recessions succeed each other. During a boom, an economy expands to the point where it is working to its full capacity so that production, employment, prices, profits and investment rates all tend to rise. During a recession, the demand for goods and services decline and economy begins to work below its potential. Output, profits, commodities and share prices generally fall. A serious long-lasting recession is called a depression or slump.

The highest point on the business cycle is called a peak, which is followed by a downturn or downswing or a period of contraction. The lowest point on the business cycle is called a trough, which is followed by a recovery or an upturn or upswing or a period of expansion. Economists sometimes describe contraction as 'negative growth'.

There are various theories as to the cause of the business cycle. Internal (or endogenous) theories consider business cycle to be self-generating, regular, and indefinitely repeating. When economic times are good or when people feel good about the future, they spend, and run up debts. A peak is reached when (or just before) people begin to consume less, for whatever reason. If interest rates rise too high, a lot of people find themselves paying more than they anticipated on their mortgage or rent, and so have to consume less. As far back as the mid-nineteenth century, it was suggested that the business cycle results from people infecting one another with optimistic or pessimistic expectations. If people are worried about the possibility of losing their jobs in the near future they tend to save more. a country's output, investment, unemployment, balance of payments, and so on, all depend on millions of decisions by consumers and industrialists on whether to spend, borrow or save.

Investment is closely linked to consumption, and only takes place when demand and output are growing. Consequently, as soon as demand stops growing at the same rate, even at a very high level, investment will drop, probably leading to a downturn. Another theory is that sooner or later during every period of economic growth - when demand is strong, and prices can easily be put up, and profits are increasing - employees will begin to demand higher wages or salaries. As a result, employers will either reduce investment, or start to lay off workers, and a downswing will begin.

External (or exogenous) theories, on the contrary, look for causes outside economic activity: scientific advances, natural disasters, elections or political shocks, demographic changes, and so on. Joseph Schumpeter believed that the business cycle is caused by major technological inventions (the steam engine, railways, automobiles, electricity, microchips, and so on), which lead to periods of ‘creative destruction'. He suggested that there was a 56-year Kondratieff cycle, named after a Russian economist. A simpler theory is that, where there is no independent central bank, the business cycle is caused by governments beginning their periods of office with a couple of years of austerity programs followed by tax cuts and monetary expansion in the two years before the next election.