New insights into cost Malmquist productivity measure

DEA-based Malmquist productivity index measures the productiv-ity change over time. Cost Malmquist index is defined in terms of input cost rather than input quantity distance functions. Hence, productivity change is decomposed into overall efficiency and cost technical change. In this paper, we provide an extension to the cost Malmquist approach by further analyzing these two cost Malmquist components. Our pro-posed approach not only reveals patterns of productivity change and presents a new interpretation along with the managerial implication of each Malmquist component, but also identifies the strategy shifts of individual DMUs in particular time period.