Does an N-shaped association exist between pollution and ICT in Turkey? ARDL and quantile regression approaches.

It is a debated issue that the influence of information and communications technologies (ICTs) on the environment is positive or negative in the literature. For instance, usage and disposal of ICTs may lead to environmental degradation and it may also increase carbon emission arising from electricity generation. However, ICT applications may contribute to environmental quality creating great opportunities for smarter cities, transport systems, electrical grids, and industrial processes. These two effects reveal the possible relationship of an inverted U-shaped association also known as the environmental Kuznets curve (EKC) hypothesis relationship between ICT and CO2. The objective of this study is to determine the structure of the relationship between environmental degradation and ICTs in Turkey for 1980-2017. The findings of the autoregressive distributed lag (ARDL) analysis indicate the validity of inverted N-shaped EKC hypothesis. However, the results of the quantile regression test are inconsistent with those of ARDL. When the coefficients from 30th to 95th quantiles are examined, it is observed that there is an inverted N-shaped relationship between ICT and CO2, but these coefficients are not statistically significant. In addition, in the 95th quantile, coefficients of the square of ICT and ICT are statistically significant, contrary to the cube of ICT which is not. This reveals that the relationship between the variables is U-shaped.