Worldwide vs Territorial Tax System: Policy Tradeoffs

A worldwide tax system taxes a multinational corporation on all income, wherever earned; a territorial system taxes only income earned within the nation. Each creates different incentives for investment, profit-shifting, and revenue, with tradeoffs that pit domestic fairness against global competitiveness.

The United States and most large economies have converged toward one of these two poles. The choice shapes how multinationals operate, where they invest, and whether tax revenue stays at home or flows abroad. There is no “right” answer, only different costs and winners.

Worldwide Systems: The US Model

Under a worldwide system, a resident corporation pays tax to its home country on all income, regardless of where it was earned. A US corporation earning $100 million domestically and $50 million in Ireland is liable for US corporate income tax on $150 million.

This sounds fair in the abstract—all income is treated equally. But it creates a practical problem: double taxation. The $50 million earned in Ireland is already taxed by Ireland. If the US then taxes it again at a higher rate, the company faces a combined rate that may be punitive.

To avoid discouraging investment abroad, worldwide systems offer a foreign tax credit. If Ireland taxed the $50 million at 15%, the corporation can credit that $7.5 million against its US tax bill. If the US rate is 21%, the corporation owes an additional $3 million to the US (21% of $50 million, less the $7.5 credit), for a total rate of 36%.

The foreign tax credit prevents the double taxation. But if the foreign rate is lower than the home rate—Ireland at 15% versus the US at 21%—the corporation still faces incentive to shift profits to Ireland. By lowering taxable income in the US and raising it in Ireland, the corporation saves 6 percentage points on that income.

Territorial Systems: The Simpler Route

Under a territorial system, corporations are taxed only on income earned within the territory. A Canadian corporation earning $100 million in Canada pays Canadian tax; income earned in Ireland is not taxed in Canada at all.

This eliminates double taxation and simplifies compliance. It is also neutral to investment location—the tax system does not penalize or reward foreign investment.

But it creates a different incentive: profit shifting outward. If a Canadian corporation earns $50 million in Ireland but can avoid Canadian tax on it, it has strong motivation to shift as much income as possible to Ireland. By structuring the Irish subsidiary to own valuable intellectual property or management services, the corporation can shift profits out of Canada via transfer pricing—internal charges between subsidiaries.

The Irish subsidiary buys low, sells high, or charges licensing fees that move money out of Canada at favorable rates. This is legal profit-shifting, not evasion. But it erodes the home country’s tax base.

Revenue and Fairness Implications

Worldwide systems typically raise more revenue in theory. By taxing all income, they capture profits that would otherwise escape in a territorial system. But because worldwide systems incentivize profit-shifting to low-tax countries, actual revenue may be less than headline estimates. Corporations invest in tax planning; multinationals hire specialists to minimize tax via transfer pricing, debt financing, and entity structure.

Territorial systems raise less revenue, especially from multinationals. Income shifted out is lost tax. But the compliance burden is lighter—corporations don’t have to track, convert, and defend foreign income taxation in multiple jurisdictions. Small and mid-market companies especially benefit; they lack the resources for sophisticated tax planning.

On fairness, worldwide systems appear more equitable—all income is treated alike. But the double-taxation problem (before the credit) creates pressure to shift profits. Territorial systems are simpler and encourage genuine foreign investment, but they risk hollowing out the domestic tax base if profits are aggressively shifted abroad.

Profit-Shifting Mechanisms

In a worldwide system: A multinational can reduce US tax by shifting profits to low-tax countries. Mechanisms include:

• Transfer pricing. A US subsidiary sells products to a foreign subsidiary at an artificially low price, moving profits abroad.
• Debt financing. The parent borrows heavily and lends to the US subsidiary at high interest rates, deducting interest in the US while moving funds abroad.
• Intangible placement. The corporation places patents, trademarks, and copyrights in low-tax jurisdictions; the US subsidiary pays licensing fees, deducting them in the US.

In a territorial system: A multinational can shift profits out of the home country (and avoid home-country tax entirely) via similar mechanisms, but the incentive is even stronger because the foreign country offers complete exemption, not just a lower rate.

Current Global Response: Minimum Tax

The international community has increasingly recognized that both systems create problems. In 2023, the OECD finalized a global minimum tax agreement: a 15% floor on corporate tax rates worldwide. Signatory countries agree not to undercut 15%; if a country’s rate falls below 15%, other countries can impose a tax to bring the effective rate up.

This partially addresses the incentive to shift profits to ultra-low-tax havens. It does not eliminate the difference between worldwide and territorial systems, but it reduces the tax-rate arbitrage that drives profit-shifting.

Case Study: US Transition

The United States has occupied both ends of the spectrum. Until 2017, it was nominally worldwide but with a major loophole: income earned abroad was not taxed until it was repatriated (brought back to the US). Multinationals used this to accumulate huge foreign cash balances, avoiding US tax indefinitely.

In 2017, the US shifted closer to territorial. The Tax Cuts and Jobs Act:

• Imposed a one-time tax on accumulated foreign profits (a partial repatriation tax).
• Moved to a “participation exemption”—foreign subsidiary income is mostly not taxed in the US.
• Introduced “Global Intangible Low-Taxed Income” (GILTI), a minimum tax on certain foreign income if the foreign rate is too low.

The result is a hybrid: nominally closer to territorial (foreign income is mostly exempt), but with a floor (GILTI ensures some tax on very-low-tax foreign income). It reflects the tension between the two poles.

Tradeoffs Summary

Which System Wins?

Neither. The choice reflects national priorities:

• Developing countries often prefer territorial (simpler administration, fewer resources for enforcement).
• High-tax countries with large multinationals (US, UK, Japan historically) have used worldwide systems to retain revenue.
• Open, investment-dependent economies (Canada, Australia) have shifted to territorial to remain competitive.
• Small economies (Ireland, Singapore, Luxembourg) have used territorial low-tax systems as a competitive advantage.

As labor and capital mobility increase, and as multinational profit-shifting has become more sophisticated, many countries have moved toward territorial systems or hybrid approaches. The global minimum tax is an attempt to set a floor without dictating the choice.

See also