Combining time DEA scores using a dynamic panel data model

We define a combined DEA score to evaluate efficiency in agricultural research. The production model we propose considers efficiency measurements under variable returns to scale for each year in the period 2012–2017. We postulate a first-order autoregressive process in the presence of covariates, to explain efficiency. Powers of the autocorrelation coefficient estimated assuming a dynamic panel specification, are used as weights to determine a combined efficiency score. A higher weight is given to recent efficiency measurements. We use a fractional regression model to investigate the statistical significance of covariates on the combined score further.