Over the last 10 years, the world is getting richer - but are we also getting happier? While wealth may be on the rise - so are sea levels, air pollution, and mental health disorders. Despite economic growth, it seems we sometimes fail to convert our wealth into wellbeing. So where should we invest our resources most effectively to improve quality of life? To help us address this difficult question, The Happiness Research Institute and Leaps by Bayer have developed a new impact metric to help better prioritize investment in breakthrough innovations. The metric we propose considers progress in terms of gains or losses in Wellbeing Adjusted Life Years (or WALYs), and is rooted in decades of research and extensively validated measures of subjective wellbeing. WALY serves as a KPI where costs and benefits are combined into a single unit of effect, and we have successfully applied it to evaluate the 'Happiness Return on Investment' on both health outcomes and environmental impact.