We give a simple, constructive proof that the lens condition implies the factor-price equalization condition, when there are only two factors. Taking stock of the sufficient conditions under which the lens condition implies the FPE condition, we have the conditions of two factors or two goods or...

The authors give a simple, constructive proof that the lens condition implies the factor price equalization condition when there are only two factors. Taking stock of the conditions under which the lens condition is equivalent to the factor price equalization condition, there are the conditions...