3.3 均衡价格理论的应用微观经济学的核心是要论证通过价格机制能够对社会经济自发地做出合理的调节，事实上价格机制的调节作用并不像理论上所讲的那样完善，比如某些生活必须品严重短缺时，价格会大幅度提高，在此价格水平上，收入水平低的家庭便难以维持最低水平的生活，从而不利于社会稳定。

因而政府有必要通过制定价格政策来克服这些副作用。

政府常用的价格政策主要有限制价格和支持价格政策。

一、限制价格Maximum price A price ceiling set by the government or some other agency. The price is not allowed to rise above this level (although it is allowed to fall below it).Rationing Where the government restricts the amount of a good that people are allowed to buy.The government may set maximum prices to prevent them from rising above a certain level. This will normally be done for reasons of fairness. In wartime, or times of famine, the government may set maximum prices for basic goods so that poor people can afford to buy them.The resulting shortages, however, create further problems. If the government merely sets prices and does not intervene further, the shortages will lead to the following:●Allocation on a ‘first come, first serve’ basis.●Firms deciding which customers should be allowed to buy: for example,giving preference to regular customers.Neither of the above may be considered fair. Certain needy people may be forced to go without. Therefore, the government may adopt a system of rationing. People could be issued with a set number of coupons for each item rationed.A major problem with maximum prices is likely to be the emergence of black markets, where customers, unable to buy enough in legal markets, may well be prepared to pay very high prices.Another problem is that the maximum prices reduce the quantity produced ofan already scarce commodity.To minimize these types of problem the government may attempt to reduce the shortage by encouraging supply: by drawing on stores, by direct government production, or by giving subsidies or tax relief to firms. Alternatively, it may attempt to reduce demand: by the production of more alternative goods or by controlling people’s incomes.Minimum price A price floor set by the government or some other agency. The price is not allowed to fall below this level (although it is allowed to rise above it).Black markets Where people ignore the government’s price and/or quantity controls and sell illegally at whatever price equates illegal demand and supply. The government sets minimum prices to prevent them from falling below a certain level. It may do this for various reasons:●To protect producer s’ incomes.●To create a surplus, e.g. grains. Particular in periods of glut, which can bestored in preparation for possible future shortages.●In the case of wages (the price of labor), minimum wage legislations canbe used to prevent workers’ wage rates from falling below a certain level. The government can use various methods to deal with the surpluses associated with minimum prices.●The government could buy the surplus and store it, destroy it or sell itabroad in another markets.●Supply could be artificially lowered by restricting producers to particularquotas.●Demand could be raised by advertising, by finding alternative uses for thegoods, or by reducing consumption of substitute goods (e.g. by imposing taxes or quotas on substitutes, such as imports).One of the problems with minimum prices is that firms with surpluses on their hands may try to evade the price control and cut their prices.Another problem is that high prices may cushion inefficiency. Firms may feel less need to find more efficient methods of production and to cut their costs iftheir profits are being protected by the high price. Also the high price may discourage firms from producing alternative goods which they could produce more efficiently or which are in higher demand, but which nevertheless have a lower price.限制价格是指政府为了限制某些生活必需品的物价上涨而规定的这些商品的最高价格，限制价格低于市场均衡价格。

如图3-5所示，某商品由供求关系所决定的均衡价格为P o，均衡数量为Q o，但在这一价格水平时，部分生活贫困的人将买不起，因而政府对这一部分商品实行限制价格政策，限制价格为P1，P1＜P o，此时商品实际供给量为Q S，需求量为Q D，供给量小于需求量，产品供不应求。

因而为了维持限制价格，政府就要实行配给制。

限制价格的影响作用可以利用住房的限制价格为例来说明：第一，导致住房供给严重不足。

在计划经济体制下，决定住房供给的并不是价格，而是国家计划。

所以，住房不足的基本原因不能完全归咎于租金的高低，但应该指出，除了计划失误外，房租过低也是原因之一。

由于房租过低，甚至比住房的维修费用还少，这就造成住房部门资金严重不足，建房困难。

第二，寻求活动、黑市和寻租。

在房租受到严格管制，住房严重短缺的情况下，就会产生寻求活动和黑市。

在我国公有单位住房是由各单位拥有的住房占绝大多数。

在这种情况下，寻求活动就是：想尽办法分到国家住房，这种想办法走门子就是一种寻求活动。

这种寻求活动增加了住房的交易成本。

黑市活动包括两方面：以极高的价格租用私人住房，以及个人把分配到的住房高价出租。

除了寻求活动和黑市外，在租金受到严格限制，住房采取配给的情况下，必然产生寻租现象。

这就表现在，掌握分配住房的人，利用权力接受贿赂。

解决住房问题的出路，一是住房市场化。

一方面通过有偿转让使公有住房私有化。

另一方面开放对房租限制，由住房市场的供求决定房租。

二是创造住房市场化条件。

我国实行住房市场化，由于职工收入水平低，工资中实际不包括买房支出，以及住房的分配不公平等因素，造成严重困难。

因而我们必须创造条件，推动住房市场化。