Bootstrap DEA is a valuable tool for gauging the sensitivity of DEA scores towards sampling variations, hence allowing for statistical inference. However, it is associated with generous assumptions while evidence on its performance is limited. This thesis begins with the evaluation of the performance of bootstrap DEA in small samples through a variety of Monte Carlo simulations. The results indicate cases under which bootstrap DEA may underperform and it shown how the violation of the fundamental assumption of equal bootstrap and DEA biases may affect confidence intervals and cause the evidenced underperformance. An alternative approach, which utilises the Pearson system random number generator, seems to perform well towards this respect. In particular, coverage probabilities converge to the nominal ones for samples as small as 120 observations and the bootstrap biases are very close to the DEA ones. In the presence of technological heterogeneity, though, poor performance is observed in all cases, which is not surprising as even the applicability of simple DEA is questionable. Using an illustrative example from the deregulation of the Greek banking sector during late 80s, potential differences arising from the various approaches are discussed. In particular, the theoretical explorations are extended to the case of the Global Malmquist productivity index, which is used to examine the productivity change of Greek banks during (de)regulation. Some differences are observed on the magnitudes of the estimated quantities of interest and on the probability masses at the tails of the relevant bootstrap distributions. Qualitatively, though, the overall conclusions are very similar; the provision of commercial freedoms enhanced the productivity of commercial banks whereas the imposition of prudential controls had the opposite effect. This result is of topical interest as the European Supervisory Mechanism, which recently assumed duties, will closely supervise “significant institutions” which includes the 4 biggest Greek banks and their banking subsidiaries.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:637119 |
| Date | January 2014 |
| Creators | Tziogkidis, Panagiotis |
| Publisher | Cardiff University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://orca.cf.ac.uk/69982/ |
Page generated in 0.0015 seconds