In 1998 Italy introduced a restricted version of an Allowance for Corporate Equity, called Dual Income Tax. Using data integrating Italy’s Institute for Statistics enterprise survey data and company accounts, we explore the effects of the Dual Income Tax on enterprise performance in 1998-2001. Firms benefiting from this allowance are simulated through the DIECOFIS corporate tax microsimulation model. The method to estimate enterprise performance is based on a structural equation model which allows us to compute a composite indicator given specific factors observed from enterprise activity. We find a positive impact of the Dual Income Tax on enterprise performance in that companies benefiting from this allowance outperformed non-eligible ones.