Table 2.
Definition of variables and data sources
| Variable | Description | Expected sign | Source |
|---|---|---|---|
| CO2 | CO2 emissions (kg per 2010 US$ of GDP) | N/A | WDI |
| EFP | Ecological Footprint in million gha | N/A | Global Footprint Network |
| EI | Energy intensity, kilograms of oil equivalent | Positive | WDI |
| EPU | World uncertainty index that deals with the frequency of articles, which contain “uncertainty” – as shown in EIU reports | Positive or negative | https://fred.stlouisfed.org/series/WUIZAF, accessed on 22 February 2022 |
| TECH | Technological innovation is measured by gross domestic spending on R&D (% GDP) | Negative or positive | WDI |
| OPEN | Trade openness is computed as composite trade intensity introduced by Squalli and Wilson (2011) capturing trade effect | Positive or negative | WDI, Authors |
| SE | Real GDP per capita capturing scale effect | Positive | WDI |
| TE | Real GDP per capita squared capturing technique effect | Negative | WDI, Authors |
| REC | Renewable energy consumption, which includes hydroelectric power, geothermal, solar, wind, and biomass is measured in British thermal unit (BTU) | Positive or negative | WDI |
| NREC | Non-renewable energy consumption comprising petroleum, natural gas, and coal is measured in BTU | Positive or negative | WDI |
| ECI | Economic complexity index is measured by a country’s diversity of exports and its ubiquity | Positive or negative | OEC 2020 |
N/A: Not available; WDI: World Development Indicators; EIU: Economist Intelligence Unit