The goal of the present research is to contribute to the detection of tax fraud concerning personal income tax returns (IRPF, in Spanish) filed in Spain, through the use of Machine Learning advanced predictive tools, by applying Multilayer Perceptron neural network (MLP) models. The possibilities springing from these techniques have been applied to a broad range of personal income return data supplied by the Institute of Fiscal Studies (IEF). The use of the neural networks enabled taxpayer segmentation as well as calculation of the probability concerning an individual taxpayer’s propensity to attempt to evade taxes. The results showed that the selected model has an efficiency rate of 84.3%, implying an improvement in relation to other models utilized in tax fraud detection. The proposal can be generalized to quantify an individual’s propensity to commit fraud with regards to other kinds of taxes. These models will support tax offices to help them arrive at the best decisions regarding action plans to combat tax fraud.

Interest in public infrastructure research has been a subject of increasing concern to economists and policy-makers. This article aims at analysing the locational impact of the high capacity roads (HCR) on the Spanish private economic activity from 1970 through 1998, given that this is one of main infrastructure-based development strategy undertaken in Spain in this period. In a stochastic frontier production-function framework, we allow for modelling of provincial heterogeneity through the existence of different efficiency levels in the territorial units. Results show HCR spillovers between geographically close provinces and between provinces displaying similar socio-demographic characteristics and government size. To the extent that the magnitude and sign of these impacts differ across sectors a reasonable explanation of the limited impact of HCR on aggregate private production could be made. The presence of a negative spillover effect in the industrial and business service sector suggests that Spanish provinces may have used HCR capital as a competitive tool for attracting factors of production leading to a rearrangement in these economic activities.