but it doesn't necessarily hold in a given year

不过在特定年份有可能不成立
because there are other things that affect price.

因为还有其他影响价格的因素
This is what I was saying--that arbitrage enforces fair value.

这就是我一直在说的套利产生公允价值
There is a problem if there is no grain in storage.

如果没有谷物仓储会产生一个问题
For example, right at the harvest end when the harvest is coming in,

比如在下一个收割季来临之前
the relation between futures and spot price can become very erratic.

期货和现货的价格关系会出现异常
The futures price can be way below the fair value;

期货价格可能会低于公允价值
the right hand side--spot times one plus R plus S--

右侧这个现货价格加R加S
is called fair value.

称为公允价值
Futures can be below fair value

期货价格可能低于公允价值
and there's no way for arbitrage to make up the difference

并且没有套利机会可以修复这个差异
because there's nothing--if the futures were very low,

因为当期货价格很低时