In recent years, many studies have been carried out on the relationship between institutions and happiness. Although it is accepted that institutions are an important factor on happiness, that relationship may vary according to the countries, income level and time. In this study, the relationship between institutions and happiness for the period 2006-2019 in 93 countries is investigated by using three-dimensional panel data model with two units of country and per capita income and a time dimension. The findings obtained from the fixed and random effects estimators show that institutional quality has a positive effect on happiness. In addition, due to the existence of per capita income effect, the sample was divided into four groups and two-dimensional analysis is also employed. Findings show that the effect of institutional quality on happiness is negative in countries with low per capita income and positive in others.

Income inequality has shown as one of the most important economic problem now. Behind individual specific, economic, social, political factors, also institutional factors effect income inequality. Lower income inequality has expected with higher institutional quality. This study investigates the relationship between institutional quality and income inequality in 23 OECD countries, using fixed and random panel estimation approach and annual data over the period of 1984-2011. Evidence from a panel data estimation shows that a negative relationship between institutional quality and income inequality exist. According to this result, institutional quality is an essential tool for reducing income inequality.

Foreign direct investment (FDI) and ecological footprint (EFP) has exhibited a notable surge in Turkey since the 1980s. It is widely acknowledged that FDI can have a significant impact on ecological changes. The phenomenon whereby FDI contributes to environmental degradation is commonly referred to as the pollution haven hypothesis, whereas the converse phenomenon, whereby FDI mitigates environmental degradation, is known as the pollution halo hypothesis. On the other hand, institutional quality has a significant impact on the FDI-EFP relationship. In this study, the environmental effects of FDI in Turkey for the period 1984–2018 are examined employing time series with Fourier extension, considering the institutional quality. Fourier function models give more effective results in modeling structural breaks. Initially, the Fourier techniques are used to explore the unit root and cointegration relationship. Then, following cointegration, the DOLS estimator extended with Fourier terms are employed to derive the long-term coefficients. Ultimately, the causal relationship between the variables is examined through with the Fourier causality test. The results highlight that FDI increases environmental degradation (pollution haven hypothesis valid), whereas the interaction between FDI and institutional quality reduces environmental degradation (pollution halo hypothesis is valid). Based on these empirical results, this research suggests that enhancing the institutional quality in Turkey is likely to amplify the environmental advantages of FDI besides its economic benefits.

The increasing trend in production and consumption rates, as well as the effects of industrialization and globalization, all contribute to an increase in the amount of wastes generated. The idea that the growing amount of waste, which has harmful effects on the environment and health, should be channeled into opportunities that will generate economic benefits has gained interest in recent years. As a result, the circular economy's take-make-remake perspective has begun to take the place of the linear economy's take-make-dispose perspective. It is assumed that wastes can be a potential secondary raw material, can be converted into energy, and can provide economic benefits through trade in used goods. These benefits can all be found within the framework of the circular economy, in which waste reduction, recycling, and reuse strategies are adopted. Because of national policies by itself won't be enough to maintain the sustainability of circular economy strategies on a global scale, waste trade between countries is essential. In this context, it is aimed to direct wastes to countries with comparative advantage in terms of classification and processing processes, and thus to provide economic gains on a global scale, with waste trade between countries. Based on the gravity model, the study aims to identify the variables influencing Turkey's import of waste, which is significant in the global import of waste. Using annual data for the period 2006 to 2020, the Poisson Pseudo Maximum Likelihood (PPML) method was used to examine the factors influencing Turkey's imports of waste from 63 trading partners. As a result of the analysis, it has been determined that the growth in the population and income level of the exporting country has an increasing impact on Turkey's imports of waste. The analysis also showed that Turkey's waste imports are constrained by the landlocked countries of the waste exporter countries as well as the improvements in the environmental performance and corruption control of the waste exporter country.