Dynamics of green economic development in countries joining the belt and road initiative: Is it driven by green investment transformation?

Green investment transformation is the main interval difference of the Belt and Road Initiative, however, its actual effects are still uncertain. Finding out its utility, mechanism and improvement on green economy may accelerate green development. In this paper, Slack Based Measure model is used to obtain original results, Super-Efficiency model is used to sort effective decision-making units for stronger efficient frontier and Minimum Distance to Strong Efficient Frontier model is used to narrow gaps between non-effective ones and real situations. Then Global Malmquist-Lunberger index makes results dynamisation. Samples of 51 countries joining the Belt and Road Initiative from 2008 to 2022 are used in above-mentioned models to portray green economic dynamics. Then utility, mechanism and improvement of green investment transformation on green economy are studied through econometric model. The findings show that (i) Green Belt and Road Initiative makes green economic development more stable. The standard deviation decreases by 96.53% and mean maintains in 1.5. However, disconnection between a 36.36% increase of pure technological change and a 24.83% decline of its scale effect inhibits technical advance. (ii) Share of countries obtaining green scale revenues reaches 56.86%, which realizes a 52.64% increase. Furthermore, gaps between countries with positive status and those with negative status narrow 68.42%. Positive group accounts for 50% in developed countries and 46.15% in developing countries. (iii) Performance of Green Belt and Road Initiative is better than the Belt and Road Initiative. A one standard deviation increase in green investment transformation increases green economic development by 0.2705 (0.2105), which is a 18.57% (14.45%) increase relative to average green economic development of 1.457. Former's strengths also reflect in different quantiles, lagging effect and heterogeneity analysis. (iv) Green investment transformation of Green Belt and Road Initiative broadens more reliable mechanism (Promote Innovation - Strict Regulation - Ensure Commercialization) based on original one (Improve Efficiency - Decrease Costs - Increase Revenues) of the Belt and Road Initiative. (v) For the green investment transformation with government subsidies, property rights protection, investment environment stability and exchange cooperation, magnitudes of its effects on green economic development have significant increases by 25.03%, 31.77%, 8.01% and 10.12% respectively. The findings not only help understand green economic status, but also support some policy insights for achieving green economy by discovering utility, mechanism and improvement of green investment transformation.