World Bank Study Reveals How International Arbitration Is Driving Foreign Investment Growth

A World Bank study finds that ICSID membership boosts foreign direct investment by approximately $19 million annually per destination country, highlighting the importance of credible international legal protections. The research also finds no significant decline in investment following arbitration disputes, emphasizing the need to balance investor confidence with government regulatory independence.

A new study by the World Bank's Development Research Group, under its Development Economics research program, has found that countries participating in international investor–state arbitration frameworks attract significantly more foreign direct investment (FDI). Published in October 2026, the research, titled Investor-State Arbitration and Foreign Investment: Evidence from ICSID Membership, was conducted by Guillermo Falcone, Guido Porto, Bob Rijkers and Daria Taglioni. Examining international investment flows between 1980 and 2024, the researchers found that membership in the International Centre for Settlement of Investment Disputes (ICSID) was associated with approximately $19 million in additional annual foreign investment per destination country from the world's 29 largest investing economies. The findings highlight how reliable legal institutions can strengthen investor confidence and support economic development.

Why Legal Protection Matters for Foreign Investment

Foreign investment helps countries expand industries, build infrastructure, create employment and introduce new technologies. However, international investors often face uncertainty when financing large projects, particularly in developing economies. Governments may change regulations, withdraw investment incentives or renegotiate contracts after companies have committed substantial capital. Such developments can reduce expected profits and discourage businesses from investing.

Investor–state dispute settlement mechanisms aim to reduce these risks by offering independent platforms where foreign investors and governments can resolve disagreements. Established in 1966, ICSID has grown from 20 contracting states at its founding to 159 in 2026, becoming a major institution for international investment arbitration.

Unlike ordinary domestic legal proceedings, ICSID provides an international framework for resolving eligible disputes. Its awards are binding and subject to limited review procedures under the ICSID Convention. However, membership does not automatically provide investors with additional legal rights or establish government consent to arbitration. These protections generally come from investment treaties, contracts and national laws.

The researchers examined whether participation in this framework encourages foreign investment by making government commitments more credible and reducing uncertainty over dispute resolution.

World Bank Research Finds Significant Investment Gains

The study analyzed bilateral foreign investment flows from 29 major investing economies, including the United States, Germany, Japan, China, France, India and Canada. Together, these countries accounted for approximately 95% of global foreign direct investment during the study period.

Researchers examined investment patterns across 191 destination economies and 66 ICSID membership events between 1984 and 2024. Using statistical methods designed to account for differences in investment patterns and membership timing, they compared investment flows before and after countries joined the institution.

The findings showed that bilateral investment flows during the four years following ICSID membership were approximately 240% higher than estimated levels without membership. Although this percentage appears exceptionally large, researchers explained that international investment flows are often uneven and unpredictable.

Approximately 77.4% of non-negative bilateral investment observations recorded zero flows, meaning that new investments could produce substantial percentage increases from initially low levels.

In monetary terms, ICSID membership was associated with approximately $640,000 in additional annual investment for each source–destination country pair. Across the 29 major investing economies, this translated into roughly $19 million in additional annual foreign investment per destination country.

The study also found that investment increased soon after membership became legally effective and remained positive in subsequent years, suggesting benefits beyond a temporary improvement in investor confidence.

Developing Economies Could Benefit from Stronger Investor Confidence

The research examined whether ICSID membership produced different results depending on countries' income levels, institutional quality and existing investment agreements.

Lower-income countries showed larger estimated investment gains than wealthier economies, suggesting that international legal protections may be especially valuable where investors face greater uncertainty. However, the researchers cautioned that statistical differences between country groups were not sufficiently clear to establish that poorer countries consistently benefit more.

The study also found limited evidence that countries with weaker government institutions experienced significantly greater benefits. This suggests that ICSID membership may strengthen investor confidence across different economic and institutional environments.

Importantly, researchers tested whether investment gains were actually driven by other developments, including bilateral investment treaties, trade agreements, economic growth, improvements in governance or recovery from armed conflict. The positive relationship generally remained robust after accounting for these factors.

The findings indicate that credible international dispute-resolution arrangements can influence investment decisions independently of broader economic reforms.

Arbitration Disputes Do Not Necessarily Discourage Investment

One of the study's most important findings challenges concerns that investor–state arbitration cases automatically damage a country's investment reputation.

By the end of 2024, publicly known treaty-based investor–state disputes had reached 1,401 cases, with approximately three-quarters initiated since 2010—many involved energy, mining, construction, transportation and other sectors requiring substantial long-term investment.

Despite the growing number of disputes, researchers found no statistically significant decline in foreign investment following a country's first arbitration case, whether handled by ICSID or another institution.

This does not mean disputes have no economic consequences. However, the findings suggest that their initiation does not systematically discourage subsequent foreign investment.

For governments, the research highlights the potential value of predictable legal systems in attracting international capital. Stronger investor confidence could support infrastructure development, business expansion, and employment opportunities, although the study did not directly measure these broader outcomes.

The researchers also emphasized that arbitration frameworks may involve litigation expenses, financial liabilities and restrictions on government policy choices. Their study did not assess these broader costs or determine whether investor–state arbitration improves overall economic welfare.

Ultimately, the findings suggest that international arbitration institutions can help countries attract foreign investment, but governments must balance investor protection with regulatory independence, public financial interests and long-term development priorities.