The “new development economics” (also called behavioral development economics) consists of microeconomic experimentation based on behavioral economics and randomized controlled trials. This approach would illuminate the close relationships between preferences, culture, and institutions and point to new political opportunities. This paper describes and analyzes the new development economics’s main components and argues that the new development economics is just like the old development economics in terms of its central assumptions, objectives, and recommendations. Despite the growing recognition that social, cultural, and institutional factors profoundly affect decision-making, old and new development economists generally lean toward the extreme reductionism of the neoclassical paradigm. It is observed that research on the essence of economic development has been neglected or treated inadequately in the school’s literature. It is suggested that the findings of the Austrian theory of dynamic efficiency, based on human action’s creative and entrepreneurial feature, may allow the development economics to overcome its analytical challenges.