The story starts with a goodbye at a small terminal: a chipped suitcase, a paper envelope, a promise to send money as soon as the first payslip clears. Multiply that scene by the millions and you have the quiet macroeconomics of our era — a transfer of youth, energy, and skills from the Global South to anywhere a wage and a roof come together. In official rhetoric, migration is social. At street level, it is a balance sheet. At planetary scale, it is climate adaptation disguised as a ticket.

What the Numbers Say — and What They Don’t

Migration out of Sub-Saharan Africa, South Asia and Latin America is increasingly led by the young. A World Bank-backed panel study finds roughly two-thirds of international migrants from Sub-Saharan Africa are between 15 and 35. South Asia’s delta districts show the same tilt: more than half of Bangladeshis leaving flood-prone regions are under 30. Latin America’s outflow has a governance accent — distrust in institutions and weak job creation push the 18–30 cohort outward even when borders harden. These figures describe movement; they don’t yet capture the cost of staying.

Climate Moves People — Indirectly, Relentlessly

Climate does not usually put people on buses by itself. It erodes crops, raises water stress, and turns second shocks into breaking points. The World Bank’s Groundswell modelling suggests internal climate migrants could number in the hundreds of millions by mid-century without deep adaptation; other research pushes the ceiling higher under weak mitigation. The early hotspots are visible: drought in the Horn of Africa, flooded char lands in South Asia, heat stress in Central America’s dry corridor. Most movement remains within national borders, and yet the cumulative effect is international: cities swell, precarious work tops out, and young workers seek exits that pay.

The Remittance Engine — Lifeline and Liability

Once abroad, the first dividend is remittances. For households in Nigeria, Nepal, the Philippines, Mexico, Egypt or Haiti, diaspora money smooths consumption, pays school fees, and buffers shocks. At scale, these flows prop up imports and become fiscal cushions. But lifelines have shadows. High fees to Sub-Saharan Africa still amputate value at the counter; tighter sender ID rules in the EU lengthen queues and raise compliance costs. Gulf payroll systems that delay or sequester a slice of wages change when cash arrives back home, turning government policies in host countries into seasonality in village markets thousands of kilometres away.

How the Exit Rewires Home Economies

Economists like to tally remittances as a positive external account item and call the day productive. That misses the domestic rewiring. In countries where remittances dominate, consumption rises faster than tradable output; the real exchange rate strengthens; non-tradables like housing become dearer; small firms without diaspora capital struggle. In Nepal, the share of remittances in GDP is among the world’s highest — a stabiliser that also masks a slow bleed of skills. In Nigeria, studies link remittance surges with welfare gains and, paradoxically, with stubborn unemployment when the cash does not meet a growing job base. Money softens the symptoms; it cannot stand in for jobs.

AML Rules, Crypto Clamps, and the Friction Tax

Europe’s updated anti-money-laundering regime and sender-verification thresholds push small-value transfers into costlier channels. Compliance is not a moral failing; it is a regressive tax when the average sender is a low-wage worker wiring the price of rent. In the Gulf, “mandatory savings” rules or payroll wallets that defer a slice of wages extend the waiting time for families dependent on predictable credit cycles. Crypto promised cheaper rails and found a thicket of licensing and wallet rules in OECD corridors. None of this is incidental. It is policy that changes how quickly a grandmother buys medicine.

Brain Drain by the Numbers, Not the Slogan

Skilled migration is the hardest debit to book. When nurses, engineers, and teachers leave, states lose more than a line on a census — they lose public investments already made. Some countries claw back gains through diaspora networks and return policies; many do not. A panel analysis links governance quality and emigration of the skilled in a feedback loop: poor institutions push talent out; the exit weakens those institutions further. It is fashionable to say remittances finance development. They finance survival; development demands institutions capable of turning savings into local opportunity.

What Would a Policy With Teeth Look Like?

First, honesty: treat youth emigration and climate mobility as macro variables, not anecdotes. Second, price friction: target remittance fees along the worst corridors and resist rules that raise costs on low-value transactions without measurable benefit. Third, design returns: scholarships and training bonds are political dynamite but can be reframed as optional programmes with clear incentives to come home. Fourth, insure the village: climate adaptation money should meet the household where decisions are made — water, transport, health — not just the capital city where speeches are written.

The Meridian’s Lens — Counting the Invisible

Officialdom counts planes and passports; markets count dollars. The missing ledger is the cost of delayed care, the price of a job that never appears, the currency of trust. If departure is the most rational act in a system that will not change, then the only honest policy is to change the system. Until then, young people will keep doing what macroeconomics taught them: arbitrage risk by moving. The great exit is not a crisis to be managed; it is a verdict to be heard.