Fellow, UCL Centre for Global Health Economics, from 2017.
Visiting Scientist, Harvard T.H. Chan School of Public Health, from 2014.
Consultant, World Bank, 2008-2014 and from 2015.
Honorary Lecturer, London School of Hygiene and Tropical Medicine, 2008-2013.
Academic Visitor, University of Oxford, 2010-2011
Economist, African Department, International Monetary Fund, 2001-2008.
Economist, Research Department, International Monetary Fund, 2000-2001.
Economist, African Department, International Monetary Fund, 1999-2000.
Teaching Assistant, London School of Economics, 1996-1999.
Research Assistant, Wuppertal Institute for Climate, Environment, and Energy, 1995-1996.
PhD in Economics, London School of Economics, 1996-2008.
MSc in Economics, University of Warwick, 1994-1995.
BSC Econ in Economics, London School of Economics, 1992-1994.
The Economics of the Global Response to HIV/AIDS, Oxford University Press, 2016.
"Effectiveness of and Financial Returns to Voluntary Medical Male Circumcision for HIV Prevention in South Africa: An Incremental Cost-Effectiveness Analysis" (with Nicole Fraser-Hurt and Marelize Gorgens), PLoS Medicine, May 2016.
Cliff Kerr and others, "Optima: A Model for HIV Epidemic Analysis, Program Prioritization, and Resource Optimization," Journal of Acquired Immune Deficiency Syndromes, Vol. 69, No. 3, pp. 365-376, 2015.
Anna Vassall and others, "Financing Essential HIV Services: A New Economic Agenda", PLoS Medicine, Vol. 10, No. 12:e1001567, 2014.
"The Macroeconomic Effect of HIV/AIDS," in: Culyer, Tony (ed.) Elsevier Encyclopaedia of Health Economics, 2013.
The Fiscal Dimension of HIV/AIDS in Botswana, South Africa, Swaziland, and Uganda, with Elizabeth Lule, World Bank, 2012.
"Framing HIV/AIDS as an Economic Development Challenge," Brown Journal of World Affairs, April 2011.
"HIV/AIDS, Economic Growth, Inequality," in: D. Sahn, The Socioeconomic Dimensions of HIV/AIDS in Africa: Challenges, Opportunities and Misconceptions, Cornell University Press, 2011.
"Determinants and Macroeconomic Impact of Remittances in Sub-Saharan Africa" (with Raju Jan Singh, Kyung-woo Lee, and MaŽlan Le Goff), Journal of African Economies, Vol. 20, No. 2, pp. 312-40 (March 2011).
"Quantifying the Impact of ICTs on Growth in Developing Economies," in: A. López-Claros, The Innovation for Development Report 2009-2010, Palgrave Macmillan, 2010.
"Financing HIV/AIDS Programs in Sub-Saharan Africa," Health Affairs, Vol. 28, No. 6, pp. 1606-16, 2009.
"Globalization and Health," in the Princeton Encyclopedia of the World Economy, Princeton University Press, 2009.
HIV and AIDS in South Asia: An Economic Development Risk, with Mariam Claeson (editors), World Bank, 2009.
"Development Impact of HIV and AIDS in South Asia," in M. Haacker and M. Claeson (eds.), HIV and AIDS in South Asia, World Bank, 2009.
"Financing the Response to HIV/AIDS: Some Fiscal and Macroeconomic Considerations," AIDS, Vol. 22, Suppl. 1, pp. S17-S22, July 2008.
"Access to Communication Services in Sub-Saharan Africa," in The Global Information Technology Report 2006/07, Palgrave Macmillan (for World Economic Forum), 2007.
"Fiscal and Macroeconomic Aspects of the HIV Pandemic," in Beck and others (eds.), The HIV Pandemic: Local and Global Implications, Oxford University Press, 2006.
"The ICT Sector and the Global Economy: Counting the Gains," in The Global Information Technology Report 2004/05, Palgrave Macmillan (for World Economic Forum), 2005.
The Macroeconomics of HIV/AIDS (editor), 2004 (Washington: IMF).
"HIV/AIDS: The Impact on the Social Fabric and the Economy," in Haacker (ed.), The Macroeconomics of HIV/AIDS (Washington: IMF), 2004.
"The Impact of HIV/AIDS on Government Finance and Public Services," in Haacker (ed.), The Macroeconomics of HIV/AIDS (Washington: IMF), 2004.
"Welfare Implications of HIV/AIDS" (with Nicholas Crafts), in: Haacker (ed.), The Macroeconomics of HIV/AIDS (Washington: IMF), 2004.
"Providing Health Services to HIV/AIDS Patients in Southern Africa," in: B. Granville (ed.), The Economics of Essential Medicines, London (RIIA) and Washington DC (Brookings Institution), 2003.
"The Information Technology Revolution" (co-author), Chapter III, World Economic Outlook, October 2001.
"The Decline of Inflation in Emerging Markets - Can It Be Maintained?" (co-author), Chapter IV, World Economic Outlook, May 2001.