Do Sustainability Index Inclusions Impact Audit Fees? Insights from the Turkish Capital Market

Sustainability influences corporate strategy and finance, with indices like the BIST Sustainability Index encouraging responsible investment. This study investigates whether inclusion in the BIST 50 Index affects audit fees for firms from 2020 to 2024, using panel data analysis. The results show that the inclusion of the sustainability index does not significantly affect audit fees. However, firm age, total assets, and group affiliation positively affect audit fees, while financial leverage has a negative effect. These findings offer insights into how sustainability performance relates to audit fees in an emerging market context, contributing to the broader literature on corporate sustainability and financial outcomes.