What shapes the influence evidence has on policy? The key lesson that emerges from this paper is the primacy of politics in shaping how evidence is used. In order to influence the policy process, the research community must understand both the technocratic and the political aspects of policymaking, and how these shape the choices and incentives of policy elites. The paper proposes guidelines for integrating political economy analysis into different stages of the research and communication process. It addresses three main questions:

The final published version of the editorial is available on the journal website. 

Stunting is associated with adverse cognitive development in childhood and adolescence, fewer years of schooling, decreased productivity, and reduced adult stature. Recovery from early stunting is possible; however, few studies explore whether those who demonstrate linear catch-up growth experience long-term cognitive deficits.

The importance of reducing childhood undernutrition has been enshrined in the United Nations' Millennium Development Goals. This study explores the relationship between alternative indicators of poverty and childhood undernutrition in developing countries within the context of a multi-national cohort study (Young Lives). Approximately 2000 children in each of four countries - Ethiopia, India (Andhra Pradesh), Peru and Vietnam - had their heights measured and were weighed when they were aged between 6 and 17 months (survey one) and again between 4.5 and 5.5 years (survey two).

Social protection policies in developing countries are an increasingly widespread method for tackling chronic poverty and vulnerability and helping families manage risk. Particular schemes often provide cash, paid work or food to poor people. Labour market protections and the linkages between cash transfers and other public services are also important. Young Lives research has examined the impacts of specific social protection schemes on children in Andhra Pradesh, Ethiopia and Peru.

High-quality early childhood care and education (ECCE) is now recognised as a core strategy for poverty reduction. There is evidence of high returns from ECCE investments, which can contribute to global policy priorities such as tackling child malnutrition, increasing children's successful participation in school, and strengthening economic development. In short, by supporting children and families early in life well-delivered ECCE can help to interrupt the cycle of poverty.

As a promise made to poor people worldwide the Millennium Development Goals remain a powerful signal of international consensus that more must be done to improve human development. Commitment to the MDGs was reiterated at the 2010 summit of G20 countries (G20 2010) in Toronto. As the UN Secretary General described: "They are the world’s quantified, time-bound targets for addressing extreme poverty, hunger and disease, and for promoting gender equality, education and environmental sustainability.