We examine Swiss retail investors’ willingness to pay (WTP) for sustainable finance products and the influence of bank advisor certification. In a hypothetical choice experiment with a randomized controlled trial (RCT), we assigned participants to either a priming treatment with a bank advisor certified in sustainable investing or a control group. We found a WTP between 1 and 1.5 percentage points of annual return for sustainable mutual funds, especially among financially literate investors. The presence of a certified green finance advisor further increased WTP between 0.2 and 0.8 percentage points, particularly for investors with low financial literacy.
