Editor's view: Value of information in the 21st century - examples from science, medicine, policy, media, and markets.

This editorial explores the concept of the 'value of information' in the 21st century through five distinct domains: science, medicine, policy, media, and markets. It uses examples to show that not all information is of equal value. Valuable information shifts probabilities assigned to our hypotheses in the most meaningful ways. It significantly alters our knowledge and understanding of our context, helps us prioritise more rational ideas, and facilitates better decision-making. This paper also addresses the necessity of a conscious observer for the value of information to exist. It develops a framework for how the brain perceives, processes, and assigns value to new information. An example with childhood memories is used to explain the incremental and disruptive shifts in understanding that information of different value can cause. Further examples illustrate how well-designed research can amplify the value of information, how long-neglected information can be rediscovered and used to radically reshape policy, and how expert crowdsourcing can prioritise ideas and democratise decision-making. They also show how key pieces of the most valuable information can redirect policies, have large real-world impact, and save lives. The role of disinformation is also addressed, particularly its power to distort our shared understanding of the related context, mislead rational activities and prompt susceptible people to prioritise irrational ideas. Mainstream media and social media can enable rapid spread of disinformation, exploiting the greater intensity of the brain's response to an unexpected surprise over the expected truth. Stock market prices, meanwhile, reflect in real time how each new information changes the perceived value of a company. Valuable information seems to have some inherent traits: relevance, i.e. it influences an observer's perception of the related beliefs or hypotheses; credibility, i.e. it needs to be trusted by an observer; and leverage, i.e. it influences an observer's ideas and decisions decisively. Where all three criteria align, information assumes a 'high value coefficient' and serves in revising prioritised ideas. Designing activities to increase this coefficient is therefore of common interest to scientists, health professionals, policymakers, journalists, and investors. As artificial intelligence accelerates the volume and speed of data production, human and machine systems alike will focus not merely on data collection, but on discerning which missing information, if generated, could enable the greatest positive impact on the real world. Ultimately, future success in science, medicine, policy, media, and markets may not necessarily be linked to gathering the largest amount information, but rather being good at identifying, generating, and acting upon the information that is most valuable.