Global Tax Authority: Institutional Design and Political Economy of Implementation

Executive Summary

This paper presents a rigorous analysis of proposals for a Global Tax Authority (GTA), examining both the technical architecture of international tax coordination and the political economy constraints that have prevented such an institution from emerging.

Three Categories of Proposals:

Technically feasible and politically possible (Years 1-5): Enhanced automatic information exchange, minimum tax coordination among willing states
Technically feasible but politically difficult (Years 5-15): Unitary taxation pilots, expanded beneficial ownership registries
Technically feasible but politically blocked (Years 15+): Full Global Tax Authority with binding enforcement

Core Finding: The primary obstacles to international tax coordination are political, not technical. The US constitutional requirement for Senate treaty ratification (67 votes), the veto power of tax haven jurisdictions, and the competitive dynamics of tax sovereignty create structural barriers.

Revenue Impact:

Optimistic scenario (OECD/G20 coordination): $150-300 billion annually
Full GTA with near-universal participation: $400-600 billion
Current political constraints: $50-100 billion through incremental improvements

1. The Revenue Loss Crisis

1.1 Magnitude of Revenue Loss

Current Estimates of Annual Revenue Loss:

Corporate profit shifting: $200-600 billion
Individual tax evasion: $200-500 billion
Digital economy base erosion: $100-200 billion
Total Range: $500 billion - $1 trillion+

1.2 Distribution of Losses

Developing countries: 4-10% of corporate tax revenue
OECD countries: 1-2% of corporate tax revenue

2. The Political Economy of International Tax Coordination

2.1 Why Tax Coordination Fails: Structural Barriers

Barrier 1: The US Senate Treaty Requirement

Constitutional Constraint: Article II, Section 2 requires two-thirds Senate approval (67 votes) for treaty ratification. Recent climate treaty failures (Paris withdrawal, Kigali blockage) demonstrate the political impossibility of securing Senate supermajorities for sovereignty-ceding agreements.

Barrier 2: Tax Haven Veto Power

Small jurisdictions (Cayman Islands, Bermuda, BVI) can block agreements through consensus mechanisms. These jurisdictions derive economic benefits from providing regulatory arbitrage services.

Barrier 3: Competitive Dynamics

The race to the bottom: Average corporate tax rates fell from 40% (1980) to 24% (2020). Individual countries face competitive disadvantages from unilateral action.

3. Institutional Designs: Three Scenarios

3.1 Scenario A: Incremental Coordination (Years 1-5)

Enhanced CRS with real-time reporting
Crypto-asset coverage
Minimum tax coordination at 15-20%
Developing country capacity building

3.2 Scenario B: Regional Pilots (Years 5-15)

EU Common Consolidated Corporate Tax Base
African Union Tax Coordination
Asia-Pacific regional framework

3.3 Scenario C: Full Global Tax Authority (Years 15+)

Requirements:

US political transformation
Tax haven business model collapse
Crisis forcing coordination

4. Implementation Pathways

Near-Term (2024-2029): Incremental Gains

Expand CRS coverage to crypto-assets
Improve developing country capacity
Regional coordination pilots

Medium-Term (2030-2039): Regional Consolidation

EU CCCTB implementation
African continental tax coordination
Coordinate regional approaches

Long-Term (2040+): Global Coordination

Multilateral treaty for global tax coordination
Binding enforcement mechanisms
Near-universal participation

Conclusion

International tax coordination is technically straightforward and politically difficult. The gap between what is possible and what is needed reflects power structures, not knowledge gaps.

The Bottom Line: Pursue incremental reforms where possible; build coalitions across regions; maintain institutional designs for future implementation if conditions shift.

Critical Caveat: This paper presents institutional designs for potential future implementation. None are currently politically feasible at global scale. Readers should approach proposals as long-term objectives requiring sustained political mobilization.