Comparative study of environmental and monetary policies in an R&D-based growth model.

ESG investment and financing is a response to global warming and toxic carbon emissions. This is because market and financial development is expected to contribute to de-carbonisation in relevant firms. However, the opposite might occur with carbon-intensive industries. An option is to introduce a carbon tax or an emissions cap but this varies across countries. The impact of environmental policies and the development of financial markets are thus relevant factors to analyse in the debate regarding the best pathways to reduce pollution. This impact is not conclusive in extant studies. In order to meet this gap and to devise effective solutions to this problem, the mechanisms behind them need to be empirically clarified. To achieve this research objective, this study analyses the impact of these factors on welfare through pollution and growth. It examines the respective regulatory regimes of environmental taxes and emission quotas, using an R&D-based growth model with a monetary component. This is to identify the relationship between pollution emissions and financial markets. Results reveal that increasing environmental taxes and reducing nominal interest rates does in fact lead to pollution reduction and economic growth, as well as an increase in the quantity of money and credit through deflation. Reducing emission allowances has a similar effect. However, under emission quotas, it is found that a reduction in the nominal interest rate affects neither pollution emissions nor economic growth, although it does affect the quantity of money and credit. This is because the Fisher effect disappears when the emission quota caps output. A U-shaped relationship between emission allowances and the amount of credit then arises. Under an emissions trading system, the relationship between pollution emissions and financial development can be a win-win relationship or a trade-off relationship. This depends on the emission quota and nominal interest rate. These results suggest that, in addition to environmental policy instruments, financial market development can contribute to decarbonisation if there is the right environmental financial policy. A mix of environmental and financial policies is thus important in linking financial market development to decarbonisation.