Robert Costanza and colleagues call for the development of an alternative metric that includes a broader set of information than gross domestic product (GDP) and better reflects human well-being (Nature 505, 283–285; 2014). Improved metrics are needed, but we believe that more understanding is gained from balancing many related metrics.

The authors tell a common story of too much reliance on a single metric and too little attention to its shortcomings as it shapes our world view and influences behaviour. For instance, current US political discussion is heavily focused on a 'jobs' metric, which also conveys an incomplete, and often misleading, message. As with GDP, this metric does not distinguish between activities that help or hurt well-being, and it does not offer much insight into social health and sustainability.

Individually, metrics can mislead and misdirect; in a set of complementary metrics, they can provide invaluable knowledge. Composite metrics are useful, but embody weighted components that impose and conceal trade-offs that should be understood and discussed.

Ironically, as we increasingly understand the complexities of how the world works, policy-makers and the public want to distil this complexity into a single metric. Improving a metric is a step forwards; improving our use of metrics would be a leap forwards.