Study on ETFEE in the BTH Region Based on the Window-SBM-Undesirable Model

Table 1

Spearman correlation test results.

Correlation coefficient	GDP	SO2
Capital	0.8896	0.4427
Labor	0.9263	0.0101
Energy	0.7870	0.6035

A significant correlation at the 0.01 level (two-tailed).