The world has suffered from a number of adverse supply shocks in recent years. First there was the credit supply shock of 2007–9 that led to a default on mortgages, a collapse in confidence in the banking system, the drying up of the inter-bank market, the freezing of lending and a global economic contraction. Then there was the COVID-19 pandemic. This shock to the the global economy led to a a fall in output and breaks in supply chains. As recovery took place, supply-side difficulties led to a surge in inflation.
Then there was the Russian invasion of Ukraine. This shock to energy and grain supplies led to rises in fuel and food prices: a cost-push inflationary shock. More recently, the closing of the Strait of Hormuz has cut off an important supply route and again sent fuel and other other prices rising.
These supply-side shocks create a dilemma for central banks. They push up inflation, but push output and employment down – a situation of ‘stagflation’.
This can be illustrated with a simple aggregate demand and supply diagram. The shock shifts the aggregate supply curve upwards to the left, illustrated by the move from SRAS1 to SRAS2. The price level rises to P2 and GDP falls to Y2.
But central bank policy is designed to affect aggregate demand, not aggregate supply. If it raises interest rates, aggregate demand will shift to the left. The price level will fall (or at least the rate of inflation will fall), but output will fall further. If it cuts interest rates, aggregate demand will shift to the right. This will help to curtail, or even reverse, the fall in GDP, but will lead to even higher prices.
For countries where their central bank has a simple inflation mandate (e.g. keeping inflation close to 2%), sticking to this target in the short term would result in higher interest rates, lower economic growth and higher unemployment – and possibly even a recession. In such cases, central banks tend to project forward beyond the short-term shock and set interest rates to target inflation in a few months’ time. Indeed, many central banks do explicitly target inflation in the medium term (1 or 2 years) rather than the short term.
Central banks, such as the US Federal Reserve Bank, which have a dual mandate of targeting inflation but also maximising employment, the trade-off between these two objectives can be stark. Getting the inflation down requires a higher rate of interest; maximising employment in the face of an adverse supply shock requires a lower rate of interest.
The short-term economic costs, let alone the human costs if the shock involves a war, can be great. People may suffer extreme hardship. The cost to the US Treasury of the first six weeks of the Iran war were estimated by the Pentagon to be some $29bn1 – which translates into higher taxes for US residents, lower government spending on non-war related items, higher government borrowing or some combination of the three. Other estimates put the cost to the US taxpayer as much higher – up to $1 trillion over the longer term.2 Then there are the costs to consumers of higher fuel and other prices, estimated at around $410 per month.3
The costs to Iranian citizens will be much higher in terms of war damage and loss of livelihood, let alone the suffering and loss of life. Then there are the costs to the rest of the world from higher prices of fuel, fertilisers and various industrial materials that are normally shipped through the Strait of Hormuz.
Long-term economic gain?
Supply shocks often expose economic vulnerabilities that can later be addressed, making supply chains more diverse and more resilient. They can give a boost to alternative technologies, such as a switch from fossil-fuels to green energy.
After the 2007–9 financial crisis, banking systems were made more robust under the Basel III system. Capital and liquidity requirements were increased and bank leverage was decreased. Many countries, such as the UK, introduced ‘ringfencing’ to separate retail banking from the riskier investment banking. This increased confidence in the banking system.
The COVID-19 pandemic gave a boost to working remotely and the establishment of more flexible work patterns. What was a necessity during lockdowns, was seen as an effective model by many companies. Fully remote or hybrid working became commonplace for many jobs that were previously done in the office. Time has allowed employers to find the best balance of in-office and remote working, with the optimum balance often varying by type of job being performed.
The rising price of oil and gas following the Russian invasion of Ukraine in February 2022, saw many countries that had been reliant on imports from Russia, accelerating their efforts to switch to renewable energy. Supply chains were re-examined and there was a move towards ‘re-shoring’, ‘near-shoring’, or ‘friend-shoring’: that is, obtaining supplies from countries that are nearer and/or more reliable as trading partners.
This approach was further boosted by the extensive tariffs imposed by the Trump second administration. One of the responses to the higher tariffs was to seek markets, both for exports and imports, away from the USA. To the extent that there is ‘re-shoring’ (substituting exports and imports for production and consumption within the country), then this amounts to deglobalisation. If this represents a move from low-cost to high-cost production and is contrary to the law of comparative advantage, then there will be a net economic loss. If, however, the reduction in risk of disruption and the boost to domestic industries allows a reduction in costs, there could be a net gain.
The most recent example of the Iran war has led many countries to reconsider sources of supply and to make their supply chains more robust and less risky. Gulf countries are considering expanding their pipeline network to avoid the Strait of Hormuz. For other countries, it is providing a further boost to green energy. Increased investment in the renewable sector will help to bring down costs and make countries less vulnerable to future conflicts involving oil-producing countries or sea passages.
To summarise: if initially adverse supply-side shocks cause a diversification and strengthening of supply chains, a diversification of energy sources, accelerated technological innovation and the adoption of new more efficient techniques, the long-term supply-side effects could be positive. Pain today for gain tomorrow?
But the short run comes before the long run and today’s costs are real and mounting. A shock may stimulate a positive response, but the current shock is persisting, and forecasts are getting more dire by the day. And even when the Iran war is over, there may be more shocks around the corner – ‘unknown unknowns’. As Keynes said: ‘In the long run we’re all dead’.
References
- Pentagon’s estimate for Iran war grows to $29B
- World Politics The Iran war could cost the American taxpayer $1 trillion, says Harvard academic
- The Economic Costs of the Iran War
Politico, Mark Sweney (12/5/26)
CNBC, Joseph Wilkins (14/4/26)
American Enterprise Institute, Roger Pielke Jr. (2/4/26)
Articles
- The Iran war could have a surprising silver lining for the global economy
- Expert: Iran war cost $72 billion over first two months
- The Economic Impact of the Iran War: A Global Supply Chain Shock
- ‘Degree of complacency’: are supply chains prepared for impact of ongoing Iran war?
- Improving resilience and economic efficiency in global supply chains to counter shocks
CNN, David Goldman (12/56/26)
Responsible Statecraft, Stavroula Pabst (7/5/26)
LSE blogs, Mina Toksöz (15/4/26)
The Guardian, Heather Stewart and Jasper Jolly (10/5/26)
World Bank blogs, Sebastien Dessus (30/9/24)
Questions
- What policies have central banks pursued during the Iran war?
- Paint an optimistic scenario for the global economy five years hence.
- Paint a pessimistic scenario for the global economy five years hence.
- Compare the sources of supply of oil and gas for Europe directly prior to the Iran war with those directly prior to the Russian invasion of Ukraine.
- Compare the relative merits of globalisation and deglobalisation. Does this depend on the nature of globalisation and deglobalisation?
With the bounce-back from the pandemic, many countries have experienced supply-chain problems. For example, the shortage of lorry drivers in the UK and elsewhere (see the blog 
If supply chains become unreliable, however, JIT can lead to serious disruptions. A hold-up in one part of the chain will have a ripple effect along the whole chain because there is little or no slack in the system. When the large container ship, the Ever Given, en route from Malaysia to Felixtowe, was wedged in the Suez canal for six days in March this year, the blockage caused shipping to be backed up. By day six, 367 container ships were waiting to transit the canal. The disruption to supply cost some £730m. 
