To this end, such decisions cannot be based on intuition or intuition. Regression analysis explicitly or implicitly guides decision makers through the process by scientifically verifying the relationship between the variables they seek to target by revealing the controllable factors. For example, a policymaker who believes that increasing investment in the education sector may find support in a regression model that shows a strong positive correlation between the two. 3. CLASSIC METHODOLOGY OF ECONOMETRYa. Economic theory of the Kuznet environmental curve: Although the origin of the EKC is well known, it dates back to studies carried out in the 1990s by Grossman and Kruger as well as the duo Shafik and Bandyopadthyay. “The environmental Kuznets curve (EKC) hypothesis postulates an inverted U-shaped relationship between different pollutants and per capita income, that is, environmental pressure increases to a certain level at as income increases; afterward, it decreases. Mathematical model of the theory: As the theory posits, the relationship between environmental factor and income would change over time. First a positive relationship which, after a certain time, turns into a negative relationship. Therefore, the following two mathematical models can be constructed: