| 2001-2006年 | | 2007-2013年 | | 纺织品 | 机械与电子产品 | 矿产品 | 纺织品 | 机械与电子产品 | 矿产品 | xc, i, t1 | 0.515*** | 0.530*** | 0.509*** | | 0.532*** | 0.600*** | 0.514*** | | (0.027) | (0.027) | (0.028) | | (0.032) | (0.019) | (0.028) | density×(1- xc,i,t1) | 1.718*** | 2.906*** | 1.699*** | | 2.454*** | 4.905*** | 1.573*** | | (0.512) | (0.806) | (0.272) | | (0.215) | (0.359) | (0.166) | density×xc, i, t1 | 1.641*** | 2.608*** | 1.880*** | | 1.881*** | 3.273*** | 1.344*** | | (0.259) | (0.540) | (0.262) | | (0.270) | (0.341) | (0.236) | City Fe | Yes | Yes | Yes | | Yes | Yes | Yes | Product Fe | Yes | Yes | Yes | | Yes | Yes | Yes | _cons | 0.022 | -0.054 | -0.023* | | -0.027 | -0.162*** | -0.008 | | (0.034) | (0.058) | (0.012) | | (0.020) | (0.031) | (0.010) | N | 46800 | 41184 | 20280 | | 46800 | 41184 | 20280 | R2 | 0.617 | 0.595 | 0.488 | | 0.596 | 0.580 | 0.459 |
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