Technical efficiency and productivity analysis of the Italian prison system: a methodological comparison

The paper presents a rigorous frontier-analysis of technical efficiency, returns to scale and the composition of productivity growth of the Italian prison system over the period 2003-2005. The study tries to fill some gaps in the literature on the subject, which mainly suffers from both small-samples applications and the lack of direct comparison between parametric and non-parametric methods. The data-panel considered accounts for almost 80% of the inmates population. Methodological analysis of the differences in their estimated results seems to argue in favour of the data envelopment models (DEA), as a better fit of a 'complex' estimated production-technology. Technical inefficiency ranks high, ranging on average from 25% to 30%. Conversely, scale inefficiency is moderate. Over the period, productivity grows by nearly 3%, with the main contribution provided by technical change (+3.17%). Finally, the analysis shows that a negative statistical correlation occurs between overcrowding and non-parametric technical efficiency.