What are twin deficits in simple terms?

When the government overspends, the country borrows more abroad and the trade gap widens.

Do they always move together?

No; it depends on saving, capital mobility and openness.

Twin Deficits

📈 Economics By CampusDown Wiki Editorial Team Last updated October 27, 2026 Views 7

The twin deficits hypothesis holds that a larger government budget deficit leads to a larger current account deficit. It gained prominence in the 1980s when US tax cuts and defence spending widened the budget deficit alongside a growing trade deficit.

Contents

1. The identity
2. Channels
3. Critiques and evidence
4. FAQ
5. References

The identity

The current account equals private saving minus investment plus public saving, so with private behaviour fixed a larger deficit worsens it. Feldstein and Horioka (1980) documented the saving–investment link.

Channels

In Mundell's (1963) framework fiscal expansion raises rates, attracts capital and appreciates the currency, cutting exports, drawing on exchange rate theory and Keynesian demand; Obstfeld and Rogoff (1996) gave an intertemporal view.

Critiques and evidence

Under Ricardian equivalence (Barro, 1974) deficits leave the current account unchanged. Chinn and Prasad (2003) found a link, Corsetti and Müller (2006) found it stronger in open economies, and Kim and Roubini (2008) found twin divergence in the US.

FAQ

What are twin deficits in simple terms?: When the government overspends, the country borrows more abroad and the trade gap widens.
Do they always move together?: No; it depends on saving, capital mobility and openness.

Sources reviewed: 2026-10-26

References

Mundell, R. A. (1963). Capital mobility and stabilization policy under fixed and flexible exchange rates. Canadian Journal of Economics and Political Science, 29(4), 475–485. Mundell–Fleming foundations.
Barro, R. J. (1974). Are government bonds net wealth? Journal of Political Economy, 82(6), 1095–1117. Ricardian equivalence.
Feldstein, M., & Horioka, C. (1980). Domestic saving and international capital flows. The Economic Journal, 90(358), 314–329. Saving–investment correlation.
Obstfeld, M., & Rogoff, K. (1996). Foundations of international macroeconomics. MIT Press. Intertemporal approach.
Chinn, M. D., & Prasad, E. S. (2003). Medium-term determinants of current accounts in industrial and developing countries: An empirical exploration. Journal of International Economics, 59(1), 47–76. Cross-country determinants.
Corsetti, G., & Müller, G. J. (2006). Twin deficits: Squaring theory, evidence and common sense. Economic Policy, 21(48), 598–638. Effects depend on openness.
Kim, S., & Roubini, N. (2008). Twin deficit or twin divergence? Fiscal policy, current account, and real exchange rate in the U.S. Journal of International Economics, 74(2), 362–383. Finds twin divergence.

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This article was last updated on October 27, 2026. It is based on widely recognized original works and textbooks; when citing it in a paper, please check the original sources listed in the references.