This doctoral thesis provides a comprehensive assessment and analysis of GDP fluctuations (volatility) in South Asian countries — their determinants and their impact on long-run economic growth and private investment. The study uses five-year moving standard deviation from the trend of GDP per capita growth rate to measure GDP fluctuations, and applies modern non-stationary panel econometric techniques — including cross-sectional dependence tests, panel unit root tests, panel cointegration, and GM-FMOLS estimation — to a panel of five South Asian countries (Bangladesh, India, Nepal, Pakistan, and Sri Lanka) over the period 1980–2010. The thesis makes an original empirical contribution to understanding growth-volatility dynamics in the South Asian development context.