Effects Of Land Supervision On Arable Land Conservation Based On PSM In China

Cultivated land protection is an important issue about the nation’s long-term survival and development and it is also one of the problems that experts and scholars pay close attention to for a long time. As the land illegal phenomena are increasing, especially the increase of the phenomenon of illegal occupation in cultivated land, for improving our country land law enforcement supervision system and strengthening supervision over the land law enforcement, and perfecting cultivated land protection policy system in our country, we establish and implement the land supervision system in our country. Research on the performance of land supervision on cultivated land protection has important theoretical and practical significance, which can enrich the domestic research on land supervision system, further improve the system of land supervision, summarize the problems existing in land supervision, improve the efficiency of supervision and the performance of land supervision on cultivated land protection. This research use big data to analyze the relationship between land illegal and land supervision. On the basis of summarizing the relationship between land supervision and illegal land and the work mechanism of land supervision, we analyze the influence of the implementation of land supervision system on cultivated land protection theoretically. Then we use the indexes of cultivated land area occupied by construction, land illegal case occurred this year involving the arable land and the reduce area of cultivated land area to estimate the performance of land supervision on cultivated land protection through the panel data model analysis method and the PSM analysis method. According to the analysis of the present study, we can draw the following main conclusions:1) The correlation between land supervision and land illegal is obvious. Based on data mining, the co-integration analysis and Granger causality analysis, the results show that:one is that the awareness of land supervision and that of land illegal is of correlation. The awareness of land supervision and that of land illegal exist bidirectional causality. The rise of the awareness of land illegal can cause the country to pay more attention to land illegal and then carry out supervision on land illegal. The establishment of the land supervision system can effectively improve the recognition of the people for the illegal use of land, and enhance the awareness of the land illegal. Secondly, land supervision awareness and land illegal case is of correlation. Land supervision awareness is the cause of illegal land case. The establishment of the land supervision system can effectively improve the recognition of the people for the illegal use of land, and strengthen the attention to the land illegal, reduce the number of illegal land cases. Land illegal case is not the cause of land supervision attention, the reduce of land illegal cases cannot explain the increase of land supervision attention. In general, the reduce of land illegal cases indicates the reduce of land illegal phenomenon, and the land supervision that takes the land illegal phenomenon as the main object will also be reduced accordingly.2) We use the indexes of cultivated land area occupied by construction, land illegal case occurred this year involving the arable land and the reduce area of cultivated land area to estimate the performance of land supervision on cultivated land protection through the panel data model analysis method and the PSM analysis method. On the whole, the total performance of special land supervision on cultivated land protection has a downward trend, the total performance of regular land supervision on cultivated land protection has a rising trend, the general effect of land supervision on cultivated land protection is on the rise. When we use the index of cultivated land area occupied by construction, the results of previous research that uses the panel data model to analyze show that because of special land supervision, it reduced cultivated land area occupied by construction by 32160.52hm2 and 6442.90hm2 in 2007 and 2008 respectively and in 2008, because of regular land supervision, it reduced cultivated land area occupied by construction by 41127.79. This study estimates that the loss of arable land due to construction use decreases 8037.489hm2 per year because of special land supervision in effect and the loss of arable land due to construction use decreases 62741.880hm2 per year because of regular land supervision in effect by PSM; When we use the index of land illegal case occurred this year involving the arable land, the results that use the panel data model to analyze show that because of special land supervision, from 2007 to 2013, it reduced land illegal case occurred this year involving the arable land by 227.29hm2、113.64hm2、170.47hm、246.23 hm2、75.76hm2、94.70hm2、151.52hm2 respectively, and from 2008 to 2013, because of regular land supervision, it reduced land illegal case occurred this year involving the arable land by 2577.80hm2、5389.95hm2、6561.67hm2、6796.02hm2、 6561.67hm2、6092.98hm2 respectively. The results that use PSM analysis method show that because of special land supervision, from 2007 to 2013, it reduced land illegal case occurred this year involving the arable land by 103.95hm2、51.98hm2、77.96hm2、112.62hm2、34.65hm2、 43.31hm2、69.30hm2 respectively, and from 2008 to 2013, because of regular land supervision, it reduced land illegal case occurred this year involving the arable land by 1276.90hm2 2669.89hm2、3250.30hm2、3366.38hm2、3250.30hm2、3018.13hm2; When we use the index of the reduce area of cultivated land area, the results that use the panel data model to analyze show that because of special land supervision, from 2007 to 2013, it reduced the reduce area of cultivated land area by 117.87khm2、30.75khm2、56.37khm2、71.75khm2、25.62khm2、30.75khm2、46.12khm2 respectively, and from 2008 to 2013, because of regular land supervision, it reduced the reduce area of cultivated land area by 23.49khm2、56.39khm2、101.81 khm2、92.41 khm2、72.05khm2 65.78khm2.The results that use PSM analysis method show that because of special land supervision, from 2007 to 2013, it reduced the reduce area of cultivated land area by 16.04khm2 4.18khm2、7.67khm2、9.76khm2、3.49khm2、4.18khm2、6.28khm2 respectively, and from 2008 to 2013, because of regular land supervision, it reduced the reduce area of cultivated land area by 7.79khm2、18.70khm2、33.77khm2、30.65khm2、23.90khm2、21.82khm2.3) When we use the indexes of cultivated land area occupied by construction and land illegal case occurred this year involving the arable land, the unit performance of regular land supervision on cultivated land protection is better than that of special land supervision, and the total performance of regular land supervision on cultivated land protection is also better than that of special land supervision; When we use the index of the reduce area of cultivated land area, the unit performance of regular land supervision on cultivated land protection is worse than that of special land supervision, but the total performance of regular land supervision on cultivated land protection is better than that of special land supervision. The possible reason is that regular supervision is a comprehensive routine supervision, the supervision range is wider, supervision frequency is higher, supervision dynamics is stronger compared with special land supervision. The goal of regular land supervision is that regular land supervision covers 126 key supervision regions every two years, and cover the nation every five years, except the parts of the west. Regular land supervision has almost covered the nation since 2008. Thus, the force of regular land supervision should be stronger than special land supervision, namely the unit performance of regular land supervision on cultivated land protection is better than that of special land supervision. But when we use the index of the reduce area of cultivated land area, the unit performance of regular land supervision on cultivated land protection is worse than that of special land supervision. The possible reason is that the reduce area of cultivated land mainly includes cultivated land area occupied by construction, agricultural structural adjustment, disaster and ecological returning farmland, but land supervision takes land illegal phenomenon as the main object, more accurately, the influence of land supervision on the cultivated land area changes should be the main influence on cultivated land area occupied by construction. Here we take the reduce area of cultivated land as explained variable obviously enlarge the scope for the interpretation of land supervision, and thus produce differences, namely the unit performance of regular land supervision on cultivated land protection is worse than that of special land supervision.4)In the evaluation of land policy, we need to consider the difference of the relationship between the policy and its object, in order to consider the choice of the method used in policy effect evaluation. The sample selection of special land supervision is not random, resulting in the effect of special land supervision on cultivated land protection larger in previous studies. The sample selection of regular land supervision is more random, resulting in the sample selection bias smaller and the effect of regular land supervision on cultivated land protection more accurate compared with the special land supervision in studies.