Natural disasters, terrorism, and war destroy value and cause real human suffering. By any common-sense measure, all three make a society worse off. Yet under the GDP system, each of them can appear to boost the economy. That is not because destruction is secretly good for growth — it is because of a specific accounting flaw in how GDP is calculated. GDP quietly conflates “the economy” with “expenditure.” It counts money spent, regardless of whether that spending is genuinely new production or simply an attempt to replace something that was just lost. Losses are never subtracted from the number; only additions are counted.

This is the same asymmetry behind the well-known broken window fallacy, applied here to three of its most consequential real-world cases: disasters, terrorism, and war.

Why Rebuilding Isn’t Growth

The core mechanism is the same across all three cases. Reconstruction after a disaster or a war looks like production, because land, labor, and capital visibly go into building something. But if that “something” merely replaces what was destroyed, the economy has not actually grown — it is simply back to where it started, at real cost.

This accounting paradox occurs because GDP is a measure of economic flow (spending and output within a timeframe), rather than economic stock (a nation’s total accumulated wealth and assets). When a disaster destroys an asset, the loss in capital stock is never subtracted from GDP; only the subsequent flow of expenditure to rebuild it is counted.

Two ways to see this clearly: losing a $100 bill in a storm and then working hard to earn another $100 back does not leave you $100 richer — it leaves you back where you started, minus the effort spent recovering. Likewise, if a country has 100 roads, a war destroys 50 of them, and the country rebuilds those 50, the GDP system records the rebuilding as growth. In reality, the country still only has 100 roads — and has spent additional resources just to get back to where it already was.

This same mechanism explains a strange asymmetry in how GDP treats disasters: a wealthy country like the United States, which can quickly fund reconstruction, tends to see a GDP increase after a disaster, while a poorer country facing the same kind of disaster — without the resources to rebuild quickly — sees a GDP decrease. The accounting is rewarding recovery capacity, not actual wellbeing; the losses themselves are never subtracted from either country’s GDP.

The Hidden Cost: What Else Those Resources Could Have Built

Every dollar and every hour spent on security, reconstruction, or war is a dollar and an hour not spent on something genuinely productive — education, healthcare, or industry. GDP has no mechanism for asking what those resources would otherwise have built; it simply assumes resources are unlimited and counts whatever they were spent on as a gain.

Economist Adam Smith drew a useful distinction in The Wealth of Nations between productive labor, which directly creates tangible goods and wealth, and what he termed ‘unproductive labor’ — such as judges, security forces, and public officials — which is necessary for societal stability but does not directly produce physical commodities. Smith’s point was not that unproductive labor is worthless, but that an economy suffers when its share grows too large: every additional person pulled into pure protection or reconstruction work is a person no longer available to produce something new.

The Human Cost GDP Doesn’t Count

Labor is the most important factor of production any economy has, and destructive events damage it directly. Natural disasters cause deaths, injuries, and displacement on a scale that GDP never accounts for — the lost hours of work and the goods that were never produced because the people who would have produced them are no longer in a position to do so.

War does the same on a larger scale. Economic activity is disrupted while conflict is underway — daily wage workers cannot earn a living, and many people simply cannot safely go to work. Beyond the immediate disruption, a substantial share of a country’s able-bodied workforce is often lost to the conflict itself, which reduces the country’s productive capacity for years afterward. None of this shows up as a subtraction in the GDP number; it simply vanishes from the calculation.

Case Study: Terrorism

Some economists argue terrorism is, perversely, good for GDP. The case usually rests on three points: terrorism forces higher spending on surveillance and intelligence (as seen after the September 11 attacks); it creates demand for new safety equipment at airports and other public spaces; and it creates jobs for security personnel, from federal agencies down to local police.

Each of these does increase spending, and GDP counts spending as growth regardless of what it is spent on. But the opportunity-cost problem applies directly here: every job created in security is a job not created in some other, genuinely productive industry. The metal, technology, and labor going into counter-terrorism equipment and personnel could otherwise have gone into something that adds real value rather than merely restoring a baseline level of safety. Terrorism may raise the GDP number, but it does so by creating an imbalance — more tax-funded jobs in security, paid for by higher taxes or cuts elsewhere, is not the same as broad-based economic growth.

Case Study: War

War affects nearly every factor of production at once:

• Livelihoods lost — economic activity is suspended while conflict is underway, and daily wage workers in particular lose income they cannot recover.
• Labor lost — able-bodied workers are deployed to fight, and a substantial share do not return, permanently reducing the country’s future productive capacity.
• Infrastructure lost — transport, communication, and other critical networks are frequently targeted and destroyed on both sides of a conflict, regardless of who wins.
• Debt created — few countries can fund a war from existing reserves, so war spending is typically financed through additional borrowing.
• Inflation created — when borrowing isn’t enough, governments turn to printing money, which erodes ordinary citizens’ purchasing power. Several of history’s worst hyperinflation episodes — in Weimar Germany, Hungary, and Zimbabwe, among others — followed major wars or domestic conflicts.

Reconstruction after a war follows the same “100 roads” logic described earlier: rebuilding what was destroyed gets counted in full as GDP growth, even though the country has, at best, only returned to where it started — at the cost of additional resources spent along the way.

There is one group for whom war spending is a genuine gain rather than a loss: defense contractors and reconstruction firms, which see higher sales and inflated contract values as a direct result of conflict. That commercial interest gives these firms a real incentive to support the idea that war is good for the economy, even though the broader economic picture — lost livelihoods, lost labor, lost infrastructure, debt, and inflation — tells a very different story.

The Bottom Line

Across disasters, terrorism, and war, GDP makes the same mistake: it adds up spending without ever subtracting what was lost, ignores what else those resources could have built, and has no way to count the human cost. None of these events leave a society better off, whatever the GDP number appears to say.