This study evaluates the regional tax incentives for business investment in Italy and addresses the following questions: (i) how much additional investment was stimulated by the government intervention; (ii) has the public financing displaced (part of) the private financing; (iii) to what extent would the outcomes on firm performance have not been achieved without the public support? The methodology consists of applying the matching approach and selects a sample of firms composed of both recipients and non-recipients such that for each subsidised firm a comparable unsubsidised counterpart is found, which is similar in every respect except for the tax benefit. An empirical model of firm’s investment behaviour has then been estimated in order to obtain the tax-price elasticity and to test the sensitivity of investment decisions to the availability of internal funds by taking into account the dynamic structure underlying capital accumulation. This new approach to evaluate tax expenditures allows us to deal with the problem of the endogeneity of firms' participation decisions as well as to account for the different channels through which tax incentives operate. Finally, the impact of the investment tax credit on TFP levels is identified by modelling the productivity dynamics at the firm level.