Achieving balanced national development and reducing interregional socio-economic disparities is a comprehensive economic challenge. In this book, regional efficiency of Croatian counties is measured and compared over the three-year period (2005-2007) using Data Envelopment Analysis. Efficient counties are identified as benchmark members, while inefficient counties are analysed in detail to determine not only the sources but also the amounts of their inefficiency in each source. Proper longitudinal monitoring of development dynamics is enabled by the application of window analysis. In order...