Box Plot from Scientific Research

The heat rates of generators in different enterprises before and after the reform. The sample size is 1,298 and 766 before and after the reform, respectively, including three types of enterprise: central SOEs, local SOEs and local private enterprises. The asterisks indicate the significance degree of between-group variation (*** P < 0.01, ** P < 0.05, * P < 0.1). P values between central SOEs and local SOEs, central SOEs and local private enterprises, and local SOEs and local private enterprises before the reform are 3.0 x 10 -10, 1.9 x 10 -23 and 0.013, respectively, whereas P values after the reform are 0.001, 0.002 and 0.36, respectively.

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