Table 2.

Correlation matrixes of inputs and outputs.

	Capital	Labor	GDP	CO2
Capital	1
Labor	0.701∗∗∗	1
GDP	0.981∗∗∗	0.689∗∗∗	1
CO2	0.913∗∗∗	0.735∗∗∗	0.932∗∗∗	1

Notes: ^∗∗∗ denotes two-tailed significance at 1% level.