Over the last two decades, attempts of airport privatization in emerging economies have seen mixed outcomes. Literature shows that though many privatized airports could achieve incremental operational efficiencies, challenges have remained in establishing public–private-partnership (PPP) arrangements that could become benchmarks. Our study attempts to address this challenge by developing a reserve price model for PPP auctions of brownfield airports. We define relationships between the variables affecting airport income and use them to forecast the net income for the concession period under different scenarios. Deviating from conventional forecasting techniques, such as time-series and regression, we adopt Gaussian fuzzy membership functions for forecasting air traffic. We also assess the impact of economic shocks on reserve prices. The findings are corroborated with the recent PPP auctions of four brownfield Indian airports. Emerging economies can contextualize and adopt the model for their brownfield airport auctions.