This paper approaches the value added method for Gross Domestic Product (GDP) measurement that explains the interrelationship between the expenditure approach and the income approach. The economic growth model is also proposed with three key elements of capital accumulation, technological innovation, and institutional reform. Although capital accumulation and technological innovation are two integrated elements in driving economic growth, institutional reforms play a key role in creating incentives that effect the transitional and steady state growth rate in the real world economy. The paper provides a theoretical insight on economic growth to understand incentives and driving forces in economic growth model.