kasvuteorian

Kasvuteorian (growth theory) is a branch of economics that studies the long-run determinants of economic growth, focusing on how output per capita evolves over time. It analyzes the roles of capital accumulation, labor force growth, technological progress, human capital, institutions, and policy. The field is commonly divided into exogenous growth theory, exemplified by the Solow–Swan model, and endogenous growth theory, developed in the 1980s and 1990s by researchers such as Paul Romer and Robert Lucas.

Exogenous models assume that technological progress occurs outside the model and drives sustained growth, while capital investment exhibits diminishing returns, leading to a steady-state growth rate determined by exogenous technological progress. The Solow residual, or total factor productivity, captures the part of growth not explained by capital and labor inputs.

Endogenous growth theories attempt to endogenize technological progress and other growth drivers. They emphasize mechanisms such as knowledge spillovers, innovation, human capital, learning by doing, and institutions. The AK model is a simple endogenous framework where output grows proportionally with capital due to constant returns to scale in capital.

Empirical work on growth theory investigates convergence across economies, the impact of saving behavior, education, R&D, trade openness, urbanization, and institutions on growth rates. Critics point to measurement issues, model uncertainty, and the mixed empirical record on absolute convergence.

Overall, kasvuteorian provides a framework for understanding why countries differ in income levels and growth trajectories, and for evaluating policies intended to raise long-run prosperity.