如果结果不匹配，请 
更多“市场反需求函数P=60-3Q，A、B两家企业成本函数分别为C…”相关的问题
A.古诺竞争均衡的价格为11
B.古诺竞争均衡下企业A的产量为5
C.古诺竞争均衡下企业B产量为4
D.古诺竞争下企业A利润为45
设某商品的需求函数为
求:
(1)需求弹性:
(2)P=3时的需求弹性:
(3)在P=3时,若价格上涨1%,总收益增加还是减少？它将变化百分之几？
假定表2-1是需求函数Qd=500-100P在一定价格范围内的需求表：
(1)求出价格2元和4元之间的需求的价格弧弹性。
(2)根据给出的需求函数，求P=2元时的需求的价格点弹性。
(3)根据该需求函数或需求表做出几何图形，利用几何方法求出P=2元时的需求的价格点弹性。它与(2)的结果相同吗？
假设某商品的需求量Q与价格p的函数关系为
其中k和r是正的常数，证明该商品的需求价格弹性|Epl=r。
1983年里根执政时，推行"实物支付计划"。以小麦市场为例，考察该计划如何奏效。
(1)假设需求函数为QD=28-2P，供给函数为QS=4+4P。P是小麦的价格，单位为美元/蒲式耳，Q是产量，单位为10亿蒲式耳，试求出自由市场均衡价格和产量。
(2)假设政府向农民支付小麦，鼓励农民将部分土地退耕，使供给减少自由市场均衡量产量的25%。用于支付的小麦来源于政府储备，数量等于退耕土地的收获量。农民可在市场上自由出售这些小麦。问农民的产量为多少？政府间接供应市场多少小麦？新的市场价格是多少？农民获益多少？消费者得益还是受损？
(3)如果政府不把小麦返送给农民，小麦将积压或变质。纳税人从该计划中受益吗？该计划存在什么潜在问题？
In 1983, the Reagan Administration introduced a new agricultural program called the Payment-in-Kind Program. To see how the program worked, let' s consider the wheat market.
a. Suppose the demand function is QD=28-2P and the supply function is QS=4+4P, where P is the price of wheat in dollars per bushel and Q is the quantity in billions of bushels. Find the free-market equilibrium price and quantity.
b. Now suppose the government wants to lower the supply of wheat by 25 percent from the free-market equilibrium by paying farmers to withdraw land from production. However, the payment is made in wheat rather than in dollars- hence the name of the program. The wheal comes from the government ' s vast reserves that resulted from previous price support programs. The amount of wheal paid is equal to the amount that could have been harvested on the land withdrawn from production. Farmers. are free to sell this wheat on the market. How much is now produced by farmers？ How much is indirectly supplied to the market by the government？ What is the new market price？ How much do the farmers gain？ Do consumers gain or lose？
c. Had the government not given the wheat back to the farmers, it would have stored or destroyed i. Do taxpayers gain from the program？ What potential problems does the program create？
利用得自格雷迪(Graddy，1995)的数据集FISH.RAW。这个数据集也曾用于第12章的计算机练习C9.现在，我们用它估计一个鱼肉需求函数。
(i)假定每个时期均衡的鱼肉需求方程可写成
所以容许需求在一周中的每一天都有所不同。把价格变量视为内生的，一致地估计需求方程参数还需要什么额外信息？
(ii)变量wavet和wave3t度量了过去几天的海浪高度。为了在估计需求方程时将wave2t和wave3t用作log(avgprc)的Ⅳ，我们还需要哪两个假定？
(ii)将log(avgprc)对周工作日虚拟变量和两个浪高指标进行回归。wave2t和wave3t联合显著吗？这个检验的p值是多少？
(iv)现在，用2SLS估计需求方程。需求价格弹性的95%置信区间是什么？所估计的弹性合理吗？
(v)求2SLS的残差ut。在用2SLS估计需求方程时增加一个滞后ut-1记住，用ut-1作为自己的工具。需求方程误差中有AR(1)序列相关的证据吗？
(vi)给定供给方程明显取决于海浪变量，为了估计供给价格弹性，我们需要哪两个假定？
(vii)在log(avgprct)的约简型方程中，周工作日虚拟变量联合显著吗？你对能够估计供给弹性有何结论？
