US-Iran talks resume, oil slips below $100, and India gets two growth upgrades in one morning

The oil price move today is a clean example of how expectations, not just physical supply, set commodity prices. When traders price oil, they are not just counting barrels in storage; they are pricing the probability of future disruption. A war that threatens the Strait of Hormuz raises that probability, so buyers pay more now to lock in supply. When diplomacy resumes, the probability of the worst outcome falls, and the price falls with it, even though not a single extra barrel has been pumped.

The harder question is whether one meeting changes anything structural. The June ceasefire lasted only weeks before both sides resumed fire. A precedent that fits here is the intermittent US-North Korea talks between 2018 and 2019: each round produced a short-lived market relief rally, but no durable agreement, and the underlying tension remained. The parallel breaks down because Iran's oil exports and the Strait matter to global supply in a way North Korea's economy does not. That makes the stakes for a genuine deal much higher, and the cost of another collapse much more visible in the price at the pump.

Two upgrades arriving together make this a good moment to think about what a GDP growth forecast actually measures and why it can be revised so sharply. GDP, the total value of goods and services produced in a country in a year, is estimated from three angles: spending, output and income. When the June-quarter data came in above expectations on all three, the agencies recalibrated their full-year numbers upward. The flash India Composite PMI (Purchasing Managers' Index, a monthly survey of whether business activity is expanding or contracting) also hit a three-month high in September, which gave the agencies a forward-looking signal to lean on.

The rate hike expectation is where the story gets interesting for an IB macro student. The RBI faces a classic short-run trade-off. Raising interest rates, the price of borrowing money, is meant to cool inflation by reducing spending. But if growth is already strong and inflation is the concern, a hike is the right call even if it slows things slightly. What I find worth watching is whether private investment, which S&P says is accelerating past 10%, holds up once borrowing costs rise. If firms have already committed to projects, a 25-basis-point move may barely register. If they are still deciding, it could tip some projects into the 'not worth it' column.

The actor whose decision matters most here is the chancellor, and the trade-off he faces is unusually tight. He has committed to extra defence spending, which costs money. He has also committed to fiscal rules, a self-imposed ceiling on how much the government can borrow relative to the size of the economy. With headroom down to perhaps £10bn to £15bn, any further overshoot in borrowing or any downward revision to growth forecasts could push him over the line. The choice then is to raise taxes, cut other spending, or change the rules. Each option carries a political cost.

The bond market reaction is the mechanism that makes this urgent rather than merely awkward. Bond vigilantes are investors who sell a government's bonds when they think its finances are deteriorating, forcing yields up. Higher yields mean the government pays more interest on every new bond it issues, which adds to the deficit, which worries investors further. The UK saw a version of this in September 2022, when the Truss government's unfunded tax cuts triggered a sharp gilt sell-off. That episode is the obvious precedent, though it breaks down here because Healey is not proposing unfunded cuts; the pressure is coming from spending commitments meeting slower-than-hoped growth. Whether that distinction reassures markets enough is the question the October budget will answer.

Sitharaman's argument is essentially about who writes the rules of the international economic system. The OECD's global minimum tax, agreed in principle in 2021, sets a floor of 15% on the corporate tax rate that large multinationals pay in any country where they operate. The idea is to stop firms shifting profits to low-tax jurisdictions. But many developing economies use below-15% tax rates, or generous exemptions, as a tool to attract foreign factories and investment. A global minimum removes that tool, which is why BRICS finance ministers argue the rules were designed for rich-country priorities.

The debate here is between two readings of what the reform actually does. Supporters say it levels the playing field and stops a race to the bottom, where countries keep cutting taxes to outbid each other for investment. Critics, including several BRICS members, say it locks in the advantages of countries that already have strong institutions and infrastructure, because those countries do not need tax incentives to attract firms. I'd argue the critics have the stronger point on the distributional question, even if the race-to-the-bottom concern is real. Whether BRICS coordination translates into actual negotiating power at the OECD, or remains a statement of intent, is what the next few years will show.