What is the Evidence of the Impact of Agricultural Trade Liberalisation on Food Security in Developing Countries? A Systematic Review

Publication Details

McCorriston, S., Hemming, D.J., Lamontagne-Godwin, J.D., Osborn, J., Parr, M.J. and Roberts, P.D. (2013) What is the evidence of the impact of agricultural trade liberalisation on food security in developing countries? A systematic review. London: EPPI-Centre, Social Science Research Unit, Institute of Education, University of London.

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Steve McCorriston, David J. Hemming, Julien D. Lamontagne-Godwin, Janice Osborn, Martin J. Parr and Philip D. Roberts
East Asia and Pacific (includes South East Asia), South Asia, Europe and CIS, Middle East and North Africa, Sub-Saharan Africa, Latin America and the Caribbean
Agriculture and Rural Development, Economic Policy
Rural Livelihoods, Trade
Equity Focus
None specified
Review Type
Effectiveness review

Main findings

Headline Findings: a summary statement

The authors outline a conceptual framework against which they analyse ex ante and ex post studies, yet find no consistent conclusions on the impact of agricultural trade liberalisation on food security. Their close review of the qualifying literature reveals 13 studies concluding that food security would increase, 10 concluding that it would decrease, and 11 with mixed results.

Evidence Base

The 34 studies report evidence from individual countries, evidence from developing countries as a group, and global evidence which investigates unilateral and multilateral trade-liberalisation reforms, including the removal of both tariffs and non-tariff barriers to agricultural trade. The studies cover East Asia and Pacific, South Asia, Europe, Middle East and North Africa, CIS, sub-Saharan Africa, and Latin America and the Caribbean. 

Implications for policy and practice

Although the authors reach no clear conclusion on the link between agricultural liberalisation and food security, they provide evidence to show that prices play a key role in post-agricultural trade-reform food-security impacts. They assert that one of the key reasons why this relationship is not well understood is because isolating the impacts of trade-liberalisation reforms from other macro-economic policies that may influence food security is particularly difficult. However, by following prices, and recognising that other macro factors also affect prices, different impacts for different groups can be identified.

Implications for further research

The authors recommend greater efforts to understand the mechanisms that link trade liberalisation and food security. Understanding is lacking, for example, on the question of whether border price differences are not being reflected at the farm or consumer level, and how wide regional disparities and trade reforms are affected by countervailing domestic policies. The authors also stress the need for greater study of how prices are transmitted over space and time, and especially a need for research which identifies and includes the factors that lead to the imperfect transmission that is regularly observed. They suggest greater collection of food-security measures at the micro level, to allow a more nuanced picture to emerge of the diverse impacts between sectors, regions, sub-populations, and so on. Lastly, they urge increased attention to vulnerability and to ways in which trade liberalisation can change risk exposure. 


While food security has improved in a number of developing countries, the number of people suffering from undernourishment is increasing in many others, notably in Africa and in several Asian countries.  Food security is said to exist ‘when all people, at all times, have physical, social and economic access to sufficient safe and nutritious food to meet their dietary needs and food preferences for an active and healthy life’ (FAO, 2002). A debate exists about whether agricultural trade liberalisation, as currently promoted by the  World Trade Organization under the Doha ‘Development’ Round, improves or worsens food security in developing countries. This debate was pushed to the forefront of international concern following the recent spikes in world commodity prices. The price rises were estimated to have pushed significant numbers of people living in low- and middle-income countries below the extreme poverty line and raised questions over whether world markets can provide adequate safeguards against domestic shocks to food security. In this context there is an urgent need to understand the relationship between agricultural trade policy and food security. 

Research objectives

To synthesise the evidence on the impacts of unilateral and multilateral agricultural trade liberalisation on a range of food-security outcomes in developing countries.


The authors include ex ante and ex post studies that refer to at least one developing country and they investigate the direct links between an agricultural trade-liberalisation intervention/policy (reforms that remove or reduce trade practices that restrict trade) and outcome measures of food security (not food supply or poverty). The authors included published and unpublished literature available in English. Using search terms accordingly, they searched databases known for agricultural economics (Agricola, CAB Direct, SSCI, IDEAS, Ebsco, Dissertations Express, National Digital Library of Theses and Dissertations, Ageconsearch, USDA’s ERS) as well as other sources (Google, Google Scholar, British Library of Development Studies, Eldis, and DFID’s Research4Development). They conducted a hand-search of the key journals (European Review of Agricultural Economics, Agricultural Economics, American Journal of Agricultural Economics and Food Policy) and of documents published by the World Bank, WTO, FAO, UNCTAD, ICTSD, IPC and IFAD.

The authors synthesised the evidence narratively and used vote-counting based on direction of effect. The authors were not able to pool data and conduct a conventional meta-analysis of the 34 included studies, due to significant variation across the trade-liberalisation reforms and timing and food-security outcomes studied, different assumptions in the models employed, inconsistent periods covered by the studies’ data and omitted variables.

Quality assessment

The review has clear inclusion criteria, and the authors search a comprehensive set of databases. The characteristics of included studies are clearly described, as are methods of synthesis. However, the systematic review has some limitations. Studies not published in English were excluded from the synthesis, and so important evidence may have been missed. The extent to which the risk of bias in the included studies is assessed is not sufficiently explained. Methodologically, studies high in risk of bias are not clearly distinguished from studies lower in risk of bias, nor are they tallied separately for their conclusions on the direction of the effect of reform on food security. However, these concerns are somewhat mitigated by the fact that the authors acknowledge a large number of limitations in the evidence reviewed and in the findings of the underlying studies, and they draw no strong policy conclusions.

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