This research explores the efficiency of social welfare expenditure in Korea by analyzing marginal productivity, scale economies, and elasticity of substitution that could be obtainable from a production function. By virtue of VES production function, such productive indicators are easily identified. If once the efficiency is revealed in the production process, it brings to a positive impact to increase the level of income. Empirical evidences are shown that the public expenditure is operated systematically in comparing with the private one. This is mainly due to the fact that the system of the public sector is well-established. It implies that an operational system for the private sector ought to be built up in a short period of time. Otherwise, increasing in expenditure by a private sector would not be helpful to improve efficiency in the production side. Accordingly, level of income.