The field of sustainable and impact investing has shown tremendous growth over the past few years. But there are still too many asset owners sitting on the sidelines; interested in impact, but not yet investing. To quote Bono – a recent high-profile convert to the cause – it seems that many “still haven’t found what they’re looking for”. So why does interest continue to outstrip activity? One reason is a dearth of scaled investment products. But there’s another significant problem: we still lack a common convention for understanding the impact in impact investing.