that the equilibrium price is equal not to

均衡价格并不等于
the average of the price of the buyers,

买家的平均价格
or the average of the price of the sellers,

也不等于卖家的平均价格
or the average of all the prices or something like that.

也不等于所有出价的平均价格
It's equal to what the marginal buyer thinks it's worth.

它等于边际买家出价的边际
So there is a critical marginal buer and marginal seller.

有关键的边际买家和卖家
They're almost indifferent to buying or selling.

这几乎和买卖无关
They could go either way.

他们可交易可不交易
They're pretty close to buying or selling.

他们很可能买卖
The price is going to turn out to be very close to that valuation of the marginal buyer.

交易价格与边际买家的估值非常接近
So somehow the margin is going to play a big so the word marginal,

在1871年发明的边际
this is an invention in 1871, is going to play a big role in economic reasoning.

将会在经济学推理中扮演重要角色