A key response to legitimacy concerns over investment arbitration has been to point to the contribution of investment treaties to significant increases in in-bound foreign investment. The authors return to this vexed question of whether treaties offer material benefits and the large literature on the topic. Through a mixed methods approach and heightened awareness of the synergies and tensions within and between methodological approaches, they: (1) analyse econometrically the impact of ISDS provisions on inbound FDI; (2) present new qualitative research on investor and host state practices and attitudes; and (3) argue that social psychological research on cultural risk cognition is useful for both framing and presenting research questions and findings. They conclude that whatever the results that emerge from empirical research findings, the form of presentation will determine whether they will be accepted by the public or fall victim to growing polarization in perceptions and positions.