Economic Evaluation of Urban Land Granting Based on a Cubic Cost Function and Time-Space Dependence: An Example of 282 Prefecture-level or Other Large-and-medium-sized Cities
基于三次成本函数和时空相依的城市土地供应经济性评价——以282 个地级及以上城市为例

Economies of urban land supply are not only the core issue of land primary supply but also a crucial factor of supply and demand elements of the land market, which directly determines the effectiveness of land market regulation. Based on a cubic cost function and the two-step system GMM estimation methods of dynamic panel data (DPD), this study used a spatial matrix weighted item and its time-lag value as instrumental variables, and developed a spatial econometric model on the basis of the cubic cost function. Economies of urban land supply granting in China were evaluated using indicators of economies of scale and scope. There were 282 prefecture-level or other large-and-medium-sized cities in China during the period 2003 to 2008 involved. Statistical data were from Statistical Yearbook of Land and Resources of China and China City Statistical Yearbook. It was found that the economies of scale of aggregated land supply granting show a trend of monotonous decrease. The best performance was Dalian City which was located in 90% fractile of 282 cities. The marginal cost and average cost levels in Dalian were 607.56 and 605.5 million Yuan/hm2, and its index value of economies of scale was 0.99 which was very close to the minimum optimal scale (MOC) levels of efficiency. From the perspective of economies of scale, it had more obvious polarization among cities. About 90% of the urban land supply was uneconomical, which was a result of extremely low scale. For a small number of large cities, there were obvious large-scale diseconomies. For example, the economies of scale index value of largest size of the supplier Tianjin in 2008 were only 0.41, while the economies of scale index value of supply granting through bidding, auction and listing (BAL) and through agreement were 0.61 and 0.23, respectively. It was also found that the supply granting through agreement had a relatively high degree of economies of scale than that of supply granting through BAL. Granting through agreement and BAL showed a non-monotonic trend of increasing first and then decreasing, but the degree of economies of scale in granting through BAL was weaker than that of the granting through agreement. The optimal size for granting through agreement and BAL ranged between 95% and 99% fractile and between median and the 80% fractile, respectively. The land supply structure comprising mainly two types of the granting through agreement and BAL still existed in a more obvious uneconomic phenomenon, even though the level of scope diseconomies decreased rapidly with the expansion of the land supply size. Results show that the supply of urban land had great potential for intensification. Mechanisms for intensive land supply should be further studied.