Trade openness alone won’t deliver growth, major review of 70 studies finds

Opening up an economy to trade and foreign investment is not a reliable growth engine on its own, according to a systematic review of more than 70 peer-reviewed studies published between 2015 and 2025. The review, which followed PRISMA guidelines and appears in the journal Digital Economy and Sustainable Development, finds that the growth effects of economic openness vary sharply across income levels, and that in some settings liberalization may even harm growth when complementary conditions are missing.

The analysis, led by Yohannis Bekele Kemiso, organized the evidence using a thematic matrix that sorted studies by country income group and by transmission channel, including trade, foreign direct investment, technology spillovers, financial flows, and human capital. Studies were included only if they offered quantitative empirical analysis of the openness-growth relationship and explicitly considered income-level heterogeneity or specific country income groups. The synthesis also weighted findings by econometric robustness, favoring studies that used generalized method of moments, instrumental variable two-stage least squares, or fixed-effects models to mitigate endogeneity bias, a persistent problem in this literature.

The headline finding is heterogeneity. Upper-middle-income countries showed consistently positive effects across multiple channels, a pattern the review describes as an endogenous feedback loop, in which growth enables further liberalization and liberalization in turn promotes additional growth. In lower-middle-income countries, foreign direct investment often matters more than trade, while evidence for low-income countries remains inconclusive and, in some cases, points to negative effects. High-income countries, by contrast, gain only modest marginal benefits from additional openness, since they have largely exhausted the catch-up potential of technology transfer and now rely more on domestic innovation.

Several country-level studies underpin these patterns. Work on South Africa using vector error correction models found that trade openness substantially influenced GDP growth, with unidirectional causality running from trade liberalization to growth, particularly in the post-BRICS period. Research on developing Asian countries documented positive long-run effects of both trade and financial openness, with bidirectional Granger causality between openness and growth, and found that upper-middle-income economies within ASEAN showed more consistent positive effects from FDI than their lower-middle-income neighbors.

For lower-middle-income economies, the review highlights evidence from Bangladesh covering 1999 to 2023, where FDI and trade openness enhanced growth through productivity improvements and financial development played an amplifying, mediating role. A study of South Asian countries estimated that a 1 percent increase in trade openness was associated with an average 0.87 percent increase in GDP in fixed-effects specifications, though effects varied considerably across countries in the region. Other work found that tariff reductions, simplified customs procedures, and regional trade agreements stimulated economic performance in South Asia, supporting the trade-led growth hypothesis.

Low-income countries present the most contested picture. A study of nine Sub-Saharan African countries produced mixed results across specifications, with negative effects in pooled ordinary least squares and insignificant effects in fixed-effects models, contradictions the authors attributed to small sample sizes and missing institutional variables. Research on ECOWAS countries found trade openness negatively related to GDP per capita in both the short and long run, prompting the recommendation that these economies be careful about depending heavily on trade liberalization as their primary source of growth. Yet the same literature suggests low-income countries may benefit substantially from FDI-driven technology transfers, provided minimum thresholds of human capital and infrastructure are met.

One of the review’s most striking quantitative results concerns a human capital threshold. A 2025 study identified a human capital development threshold of 0.7919 on a normalized scale, beyond which the impact of FDI on growth becomes positive. Below that threshold, FDI effects may be negative, because economies cannot absorb foreign technology. This builds on a foundational finding from 1998 that FDI is more productive than domestic investment only when a minimum level of human capital exists in the host economy, and on more recent evidence that cognitive ability, measured by test scores, matters more than years of schooling for attracting technology-intensive FDI.

The technology transfer channel received the strongest empirical support in the reviewed literature. Multinational corporations transmit knowledge to host economies through demonstration effects, labor mobility, vertical linkages with local suppliers, and competitive pressure. Studies of innovation spillovers from US multinational firms to Chinese domestic firms in the same geographic areas found significant local technology effects. But the review also flags a risk: larger technology gaps between foreign and domestic firms provide more room for improvement yet may exceed local absorptive capacity, turning potential gains into losses.

The review is candid about its own limitations. Publication bias, the well-documented tendency of journals to favor studies showing positive and statistically significant growth effects, may inflate estimates of openness benefits. Endogeneity and reverse causality remain unresolved, since high-growth countries are also more likely to liberalize, and many reviewed studies relied on static OLS models that assume a one-way relationship. Measurement is another weakness: defining trade openness simply as exports plus imports over GDP captures trade volume rather than trade policy, so a resource-rich country can appear open despite restrictive policies. Studies on low-income countries often rest on smaller samples and less reliable national statistics, limiting generalizability.

The policy message is that one-size-fits-all liberalization should be rejected. The review recommends sequencing reforms to prioritize human capital, infrastructure, and institutional quality before aggressively opening markets, noting that countries below critical human capital thresholds may not benefit from rapid liberalization and may be harmed by it. Institutional quality emerges as foundational across all income levels, with evidence that financial openness combined with weak governance can become a source of volatility and crisis rather than growth. The review also points to digital financial inclusion as an emerging, potentially transformative channel, reducing transaction costs and enabling small enterprises and underserved populations to participate in global trade, particularly in low-income countries with expanding digital infrastructure.

Subject of Research: How the growth effects of trade and financial openness vary across countries of different income levels

Article Title: Economic openness growth nexus across countries of different income levels: a systematic review

Article References: Kemiso, Y. B. (2026). Economic openness growth nexus across countries of different income levels: a systematic review. Digital Economy and Sustainable Development, 4(1), Article 10. https://doi.org/10.1007/s44265-026-00085-w

Image Credits: AI Generated

DOI: 10.1007/s44265-026-00085-w

Keywords: economic openness, economic growth, trade openness, foreign direct investment, systematic review, human capital, technology transfer, income levels, institutional quality, absorptive capacity, digital financial inclusion, PRISMA