他认为寒流影响的是demand,我倒觉得影响的是supply,和英文教师用书不谋而合,see:
If an early freezein Californiasours the lemon crop, the supply curve for lemons shifts to the left, as shownin Figure 5. The result is a rise in the price of lemons and a decline inconsumer surplus from A + B + C to just A. So consumer surplus declines by theamount B + C.
In the market forlemonade, the higher cost of lemons reduces the supply of lemonade, as shown inFigure 6. The result is a rise in the price of lemonade and a decline inconsumer surplus from D + E + F to just D, a loss of E + F. Note that an eventthat affects consumer surplus in one market often has effects on consumersurplus in other markets.
你们觉得呢?
我还有个疑惑,柠檬本来不就是酸的吗?变酸了是不是对做柠檬水有利呢?