||This thesis investigates the effect of human capital on the economy and impact on aggregate This thesis investigates the effect of human capital on the economy and impact on aggregate income and the process of economic growth. Human capital is examined here from two different perspectives, microeconomic and macroeconomic. The microeconomic approach deals mainly with investment in human capital, i.e. types, incentives, financing, depreciation and the investment process. A new human capital investment valuation method is introduced, the real option value, which is then applied to data from selected countries. The macroeconomic approach examines the role of human capital on the macroeconomic level by investigating the relationships between human capital and some key economic variables such as physical capital, technology, foreign direct investment and taxes. Also economic growth models using human capital and their implications are compared and tested. Some specifics and problems of measuring human capital are covered as well.