Before revision:  Our algorithm estimates the potential VAT turnover of Italian individual firms for the fiscal year 2011 and suggests that the tax gap is about 30\% of the total potential tax base. Comparisons with other methods show our technique offers a significant improvement in predictive performance .
After revision:  Our algorithm estimates the potential VAT turnover of Italian individual firms for the fiscal year 2011. The proposed method significantly boost the performance in predicting with respect to the classical parametric approaches .