“Shortage”的意思、由来-开放百科全书

In economics, a shortage or excess demand is a situation in which the demand for a product or service exceeds its supply in a market. It is the opposite of an excess supply (surplus).

Definitions

In a perfect market (one that matches a simple microeconomic model), an excess of demand will prompt sellers to increase prices until demand at that price matches the available supply, establishing market equilibrium^[1]{{citation needed|date=April 2016}}. In economic terminology, a shortage occurs when for some reason (such as government intervention, or decisions by sellers not to raise prices) the price does not rise to reach equilibrium. In this circumstance, buyers want to purchase more at the market price than the quantity of the good or service that is available, and some non-price mechanism (such as "first come, first served" or a lottery) determines which buyers are served. So in a perfect market the only thing that can cause a shortage is price.

In common use, the term "shortage" may refer to a situation where most people are unable to find a desired good at an affordable price, especially where supply problems have increased the price. "Market clearing" happens when all buyers and sellers willing to transact at the prevailing price are able to find partners. There are almost always willing buyers at a lower-than-market-clearing price; the narrower technical definition doesn't consider failure to serve this demand as a "shortage", even if it would be described that way in a social or political context (which the simple model of supply and demand does not attempt to encompass).

Causes

Effects

Decisions which result in a below-market-clearing price help some people and hurt others. In this case, shortages may be accepted because they theoretically enable a certain portion of the population to purchase a product that they couldn't afford at the market-clearing price. The cost is to those who are willing to pay for a product and either can't, or experience greater difficulty in doing so.

In the case of government intervention in the market, there is always a trade-off with positive and negative effects. For example, a price ceiling may cause a shortage, but it will also enable a certain percentage of the population to purchase a product that they couldn't afford at market costs. Economic shortages caused by higher transaction costs and opportunity costs (e.g., in the form of lost time) also mean that the distribution process is wasteful. Both of these factors contribute to a decrease in aggregate wealth.

Examples

Whether an economic shortage of a certain good or service is beneficial or detrimental to society often depends on one's ethical and political views. For instance, consider the shortage of recreational drugs discussed above, and the controversies around the use of such drugs. Likewise, consider the economic shortage of cars in the Soviet Union during the 1980s: On the one hand, people had to wait in line to buy a new car; on the other hand, cars were more affordable than they would have been at market prices.

Shortages and "longages"

Labour shortage

In its narrowest definition, a labour shortage is an economic condition in which employers believe there are insufficient qualified candidates (employees) to fill the marketplace demands for employment at a wage that is mostly employer-determined. Such a condition is sometimes referred to by economists as "an insufficiency in the labour force." An ageing population and a contracting workforce and a birth dearth may curb U.S. economic expansion for several decades, for example.^[7]

Wage factors

Wage levels have been suggested as one way to measure a labour shortage. However, that often does not match people's common perceptions. For example, if wages alone are the best measure of labour shortages, then that would imply that doctors, instead of farm workers, should be imported because doctors are far more expensive than farm workers. However, there are institutionally-imposed limits on the number of doctors that are allowed to be licensed.{{citation needed|date=May 2015}} If foreign migrant workers were not allowed into a nation, farm wages may go up but probably not enough to approach the wages of doctors.

The Atlantic slave trade (which originated in the early 17th century but ended by the early 19th century) was said to have originated from perceived shortages of agricultural labour in the Americas (particularly in the Southern United States). It was thought that bringing African labor was the only means of malaria resistance available at the time.^[8] Ironically, malaria seems to itself have been introduced to the "New World" via the slave trade.^[9]

See also

References

1. ^Tucker (2014) Economics Today
2. ^{{Cite news|title = Venezuela seizes warehouses packed with medical goods, food|url = https://www.reuters.com/article/us-venezuela-economy-idUSKCN0ID00A20141024|newspaper = Reuters|date = 2014-10-24|access-date = 2015-12-07}}
3. ^{{cite news|title=Why are Venezuelans posting pictures of empty shelves?|url=https://www.bbc.com/news/blogs-trending-30710014|accessdate=10 January 2015|agency=BBC|date=8 January 2015}}
4. ^{{cite news|last1=Cawthorne|first1=Andrew|title=In shortages-hit Venezuela, lining up becomes a profession|url=https://www.reuters.com/article/2015/01/21/us-venezuela-shortages-idUSKBN0KU1BX20150121|accessdate=17 June 2015|agency=Reuters|date=21 January 2015}}
5. ^{{cite news|last1=Schaefer Muñoz|first1=Sara|title=Despite Riches, Venezuela Starts Food Rationing; Government Rolls Out Fingerprint Scanners to Limit Purchases of Basic Goods; 'How Is it Possible We've Gotten to This Extreme'|url=https://online.wsj.com/articles/despite-riches-venezuela-starts-food-rationing-1414025667|accessdate=11 November 2014|agency=The Wall Street Journal|publisher=Dow Jones & Company Inc|date=22 October 2014}}
6. ^Video Interview with Garrett Hardin: Longages and Overpopulation Predictions Educational Communications program 803, 1990
7. ^Shrinking labour force may curb U.S. expansion for two decades
8. ^"As American as…Plasmodium vivax?"
9. ^"UCI: New World malaria linked to slave trade."