It’s what most people say they want. So how do we know how happy people are? You can’t improve or understand what you can’t measure. In a blow to happiness, we’re very good at measuring economic indices and this means we tend to focus on them. With our flagship instrument at hedonometer.org we’ve created an instrument that measures the happiness of large populations in near real time. We also link to applications of the instrument to literature, movies, and news. Our Hedonometer is based on people’s online expressions, capitalizing on data-rich social media, and we’re measuring how people present themselves to the outside world. For our first version of hedonometer.org, we’re using Twitter as a source but in principle we can expand to any data source in any language (more below). We’ll also be adding an API soon.