摘要：Changes in productivity are usually associated With technology At the firm level, this is a natural way to think about productivity. However, in aggregate analysis, measures of productivity can change even when technology does not The measures change when the proportions of farms in stable technological situations change For example, more high yielding wheat on irrigated land in Arizona increases the national average wheat yield even though technology does not change either in Arizona or Kansas Changes in the proportions of farms that are larger, Incorporated, specialized, and operated by full-time farmers affect farm-sector productivity The productivity of the farm sector is partly a function of structure
