Table 1 Research variables and description.
Variables types | Variables & Sign | Descriptions |
|---|---|---|
Explained variable | Sulfur emission (SO2) | Emission of SO2(tones)/ land area |
Explanatory variable | The Digital Economy Index (ICTU) | Constructed by a set of individual variables. |
The workforce employed in the ICT industry (ICTS) | Number of workers in the ICT industry/the space of the region (10 thousand square kilometers) | |
Control variables | Gross domestic product (GDP) | GDP - GDP of last year/ GDP of last year |
Population Density (POP) | Number of people/the space of the region (kilometers, log form) | |
Secondary industry (SDI) | Number of workers in secondary industry/ the number of workers | |
Capital Investment Level (INS) | Investment in fixed assets (billion Yuan, log form) |
