In econometrics, it is well-known that a misspecification of the model gives us a completely wrong result. Shirasago estimated an elasticity of the agricultural production function in China and obtained a very similar result to that of Japan. His result shows that the output elasticity with respect to labor is fairly large. Therefore, he was puzzled over the result because believed that China had a lot of surplus labor in agriculture.
In this paper, firstly, we used a similar model to Shirasago and obtained almost the same result. However, China is a large country with a conspicuous differences in farming products and techniques between the northern and southern parts. Therefore, secondly, we used a model which considers these regional differences. Then, we got a completely different result from that of Shirasago, i. e., we have obtained that the elasticity of labor is nearly equal to zero. Therefore, we could admit the existence of a fairly large surplus labor.
Thirdly, we estimated the elasticities in these two different regions separately. One of these findings shows that the elasticity of fertilizer in the rice regions and the elasticity of machinery in the wheat and corn regions are very large. These findings are consistent with our common understanding of Chinese agriculture. Therefore, the most important finding in this study would not be merely to show the right elasticities of Chinese agricultural production function but rather to make us realize again that a right spcification is very important in order not to get a wrong result,