No one denied the significant role of transportation infrastructure in economic development; however, it is also considered a major contributor to global warming. Therefore, to achieve sustainable development, it is imperative to transform the transport sector investment into low-carbon transportation choices. The public-private partnership investment in the transport sector could be proved a suitable tool for sustainable transport and efficiency. Therefore, we investigate the significance of public-private partnership investment (PPP) on transport emissions by incorporating the role of environmental innovation, economic growth, and population. Our preliminary findings confirm that all variables are abnormally distributed and embodied with structural breaks that distort true parameters in traditional regression. In compliance, we employ Quantile ARDL (QARDL) technique which provides more reliable results in case of non-normality, dynamic trends, and structural changes in data. The long-run empirical outcomes indicate that PPP reduces transport emissions mainly from middle (40th) to highest (95th) emissions quantiles. Similarly, environmental innovation reduces transport emissions from 60th to 95th quantiles. These results imply that the emissions-mitigating effect of PPP and environmental innovation is only pronounced at higher levels of transport emissions. The results provide valuable policy recommendations.
Read full abstract