“Protection from public health threats is one vital area where markets do not deliver efficiently. As a result, it is governments that usually bear the costs of prevention and treatment”

year than in combat. In fact, last year’s 580,000 cancer deaths exceed the roughly 430,000 battle deaths, on average, in World War I, World War II, the Korean War, the Vietnam War, and the Gulf War. Yet government spending on cancer averages approximately $4 billion per year. That is just over 0.5% of the annual military budget of roughly $718 billion.

Of course, government budget-allocation decisions are complicated and dogged by political imperatives. The US military employs some three million people, making it the single largest employer in the world, and there is substantial political pressure from some constituencies to place the highest priority on America’s military dominance.

But it is not just a matter of how much is spent; it is also a matter of when. Governments don’t wait for war to break out before investing in the military. Yet they do tend to wait for crises to erupt before they invest in fighting infectious diseases.

The world spent $15 billion on its emergency response to the SARS epidemic and $40 billion on its response to Ebola. In 1918, the crisis response to the flu pandemic cost some $17.5 trillion. Had countries spent more on mitigating the risk of such disease outbreaks – for example, by fortifying their health-care systems and promoting responsible use of antibiotics – those huge emergency payouts may not have been necessary. At the very least, they probably would have been smaller.

In this sense, the fight against infectious diseases closely resembles the fight against climate change. Though the threat is substantial, it is not immediate, so governments continue to pursue other priorities, allowing the threat to grow, largely out of sight. As a result, it is not adequately priced into the markets.

When the crisis finally erupts, the true scale of the threat will become clear. But by that point, it will be much more difficult and expensive to contain, resulting in far more casualties. Unfortunately, that point may be closer than anyone – government or investor – expects.