Lesson learned by the new Italian law on the limited tax shield on debt: much ado about nothing

Corporate finance management rules are written under the assumption that financing costs are fully deductible from taxable income. If this assumption is relaxed, such rules need to be revised. We review traditional management tools and propose a new set of guidelines for financial management. The tax reform introduced in Italy, which creates a partial tax deduction for financing costs, offers a case study to measure the impact of such rules on firm’s profitability. The general wisdom among academics and practitioners was of a further pressure on economic performance of firms due to a higher tax burden. Is this concern effective? Did Italian firms paid more taxes in the following years? We checked the effect of the new rules on a sample of 2025 large Italian firms. We did not find a deep impact. Effects are limited to one sector, characterized by operating profitability on sample mean and financial leverage below sample mean. Policy makers are now advised to fine-tune this regulation or to abandon it.