Brattle economists prepared position papers on behalf of an Italian association of airports in response to the Italian Transport Regulation Authority’s (ART) tariff model. Brattle analyzed the methodology proposed to calculate cost efficiency and estimated efficiency gains of Italian airports. Our team also developed a separate methodology to calculate the weighted average cost of capital (WACC) parameters – in particular, the risk-free rate in light of quantitative easing and an equity risk premium – and evaluated the different incentives of dual-till regulation compared to single-till regulation.