Many studies on middle income trap draw attention to the product trapt hat can be expressed as the fact that countries are stuck in the production and export of unsophisticated products. In this sense, it is stated that the role of a country in the production and export of sophisticated goods is one of the determinant factors to increase the level of income. In the literature, the concept of economic complexity, which is expressed as gaining competitiveness of complex products in terms of production and export, is noteworthy in recentyears. In this framework, relationship between the per capita GDP and the economic complexity is examined with regression analysis in this study for selected countries with high-level of income. In the analysis, in which random coefficient panel regression model is applied, a significant relationship was found between the two variables for Austria, Finland, Hong Kong, Japan, Norway,Singapore and Sweden.

This paper explores the relationship between ownership structure and firm performance, using the framework of agency theory. Given a sample of 126 Polish non-financial firms listed on the Warsaw Stock Exchange between 2016-2021, we applied fixed and random effects panel regressions with robust standard errors, tested for specification, endogeneity, cross-sectional heteroskedasticity, and serial autocorrelation. Our models identify several significant associations of adopted ownership structures with firm performance measured by accounting and market-based measures. We find that ownership concentration by the largest shareholder is negatively related to enterprise market-measured performance. Additionally, our results indicate the significance of shareholder heterogeneity.