Intra- and inter-group composite indicators using the BoD model

We extent the radial DEA model with a single constant input, often referred to as the Benefit-of-the-Doubt (BoD) model, to account for environmental or contextual differences. Based on this we estimate three types of composite indicators, namely the pooled that uses the entire sample of the evaluated units, the intra-group that accounts for within group differences, and the inter-group that reflects between group differences. In addition, we provide theoretically consistent aggregation rules for these types of composite indicators. We applied the proposed methodology to analyze the financial performance of public and private hospitals in Greece by means of financial ratios referring to their liquidity performance and to examine the extent of differences in the inter-group composite indicators between the two types of ownership both at the individual and the aggregate level.