Key points are not available for this paper at this time.
At the Fourth World Congress of the Econometric Society, a number of Symposia were held at which invited papers were given. The purpose of these Symposia was to survey as completely as possible those areas in Economic Theory and Econometrics where important research had come to light during the last few years. This volume includes papers delivered at the Congress.
Chavas et al. (Sun,) studied this question.