NO.PZ2018111302000063
问题如下：
As observed from market, the longer-term coffee future contract price is higher than near-term coffee future price. A report on the coffee market concludes -The coffee market had a global harvest that was greater than expected. Despite the large harvest, coffee futures trading activity is balanced between producers and consumers. This balanced condition is not expected to change over the next year.- Combining the above information, the shape of the coffee futures curve is most consistent with the:
选项：
A.insurance theory.
B.theory of storage.
C.hedging pressure hypothesis.
解释：
B is correct.
考点：theory of storage理论
解析：第一句话给出了咖啡的远期期货价格时高于近期期货价格的，就是处于contango，期货溢价。题目让选出符合这种情况的理论是哪种。后面又给出信息说，今年coffee丰收了，这会带来很多的储存成本，而coffee并不是稀缺的原材料，所以convenience yield并不是很高，因此储存的成本会使得期货价格高于现货价格，符合theory of storage理论。
Insurance theory中consumer 和producer并不是平衡的关系，生产者愿意以更低的价格锁定未来的卖出价格，往往会出现期货价格小于现货价格的情况。hedging pressure hypothesis中是consumer 和producer相互博弈，不平衡的关系， 商品生产者在未来要要卖出商品，考虑到商品价格下降的风险，因此其卖出商品期货。与之相反，商品消费者则想要锁定他们要购买的商品价格，因此买入商品期货。如果生产者和消费者对商品价格的影响势均力敌，那么就会产生一条水平的期货价格曲线；如果生产者卖出期货的力量更强，期货价格曲线会呈现现货溢价的状态，如果消费者对买入期货的力量更强，那么期货价格曲线会呈现期货溢价。而题目中明确说了producers and consumers is balanced，所以不能用hedging pressure hypothesis 来解释。
请老师帮忙解答：为什么activity is balanced 说明可以排除A和C？
