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Agriculture and development: A brief review of the literature

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  • Dethier, Jean-Jacques
  • Effenberger, Alexandra

Abstract

After 20 years of neglect by international donors, agriculture is now again in the headlines because high food prices are increasing food insecurity and poverty. In the coming years, it will be essential to increase food productivity and production in developing countries, especially in Sub-Saharan Africa and with smallholders. This, however, requires finding viable solutions to a number of complex technical, institutional, and policy issues, including land markets, research on seeds and inputs, agricultural extension, credit, rural infrastructure, connection to markets, rural non-farm employment, trade policy and food price stabilization. This paper reviews what the economic literature has to say on these topics. It discusses in turn the role played by agriculture in the development process and the interactions between agriculture and other economic sectors, the determinants of the Green Revolution and the foundations of agricultural growth, issues of income diversification by farmers, approaches to rural development, and issues of international trade policy and food security, which have been at the root of the crisis in agricultural commodity volatility in recent years.

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Bibliographic Info

Article provided by Elsevier in its journal Economic Systems.

Volume (Year): 36 (2012)
Issue (Month): 2 ()
Pages: 175-205

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Handle: RePEc:eee:ecosys:v:36:y:2012:i:2:p:175-205

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Keywords: Economic development; Agricultural policy; Sustainable development; Rural poverty reduction; Incomes policy and price policy; Agricultural R&D; Technology and extension services;

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  1. John Baffes & Bruce Gardner, 2003. "The transmission of world commodity prices to domestic markets under policy reforms in developing countries," Journal of Economic Policy Reform, Taylor & Francis Journals, vol. 6(3), pages 159-180.
  2. Angus Deaton & Guy Laroque, 1990. "On The Behavior of Commodity Prices," NBER Working Papers 3439, National Bureau of Economic Research, Inc.
  3. Zezza, Alberto & Winters, Paul C. & Davis, Benjamin & Carletto, Calogero & Covarrubias, Katia & Quinones, Esteban & Stamoulis, Kostas G. & Di Giuseppe, Stefania, 2007. "Rural Household Access to Assets and Agrarian Institutions: A Cross Country Comparison," 106th Seminar, October 25-27, 2007, Montpellier, France 7925, European Association of Agricultural Economists.
  4. De Janvry, Alain & Sadoulet, Elisabeth & Murgai, Rinku, 2002. "Rural development and rural policy," Handbook of Agricultural Economics, in: B. L. Gardner & G. C. Rausser (ed.), Handbook of Agricultural Economics, edition 1, volume 2, chapter 31, pages 1593-1658 Elsevier.
  5. Dercon, Stefan & Christiaensen, Luc, 2011. "Consumption risk, technology adoption and poverty traps: Evidence from Ethiopia," Journal of Development Economics, Elsevier, vol. 96(2), pages 159-173, November.
  6. Bezemer, Dirk & Headey, Derek, 2008. "Agriculture, Development, and Urban Bias," World Development, Elsevier, vol. 36(8), pages 1342-1364, August.
  7. Eastwood, Robert & Lipton, Michael & Newell, Andrew, 2010. "Farm Size," Handbook of Agricultural Economics, Elsevier.
  8. Thirtle, Colin & Lin, Lin & Piesse, Jenifer, 2003. "The Impact of Research-Led Agricultural Productivity Growth on Poverty Reduction in Africa, Asia and Latin America," World Development, Elsevier, vol. 31(12), pages 1959-1975, December.
  9. Andrew D. Foster & Mark R. Rosenzweig, 2010. "Microeconomics of Technology Adoption," Annual Review of Economics, Annual Reviews, vol. 2(1), pages 395-424, 09.
  10. Braverman, Avishay & Stiglitz, Joseph E, 1982. "Sharecropping and the Interlinking of Agrarian Markets," American Economic Review, American Economic Association, vol. 72(4), pages 695-715, September.
  11. Sen, Amartya, 1981. "Ingredients of Famine Analysis: Availability and Entitlements," The Quarterly Journal of Economics, MIT Press, vol. 96(3), pages 433-64, August.
  12. Barrett, C. B. & Reardon, T. & Webb, P., 2001. "Nonfarm income diversification and household livelihood strategies in rural Africa: concepts, dynamics, and policy implications," Food Policy, Elsevier, vol. 26(4), pages 315-331, August.
  13. Birkhaeuser, Dean & Evenson, Robert E & Feder, Gershon, 1991. "The Economic Impact of Agricultural Extension: A Review," Economic Development and Cultural Change, University of Chicago Press, vol. 39(3), pages 607-50, April.
  14. Conning, Jonathan & Kevane, Michael, 2002. "Community-Based Targeting Mechanisms for Social Safety Nets: A Critical Review," World Development, Elsevier, vol. 30(3), pages 375-394, March.
  15. Estudillo, Jonna P. & Otsuka, Keijiro, 2010. "Rural Poverty and Income Dynamics in Southeast Asia," Handbook of Agricultural Economics, Elsevier.
  16. Pan, Lei & Christiaensen, Luc, 2011. "Who is vouching for the input voucher ? decentralized targeting and elite capture in Tanzania," Policy Research Working Paper Series 5651, The World Bank.
  17. Syrquin, M. & Chenery, H.B., 1989. "Patterns Of Development, 1950 To 1983," World Bank - Discussion Papers 41, World Bank.
  18. Anderson, Kym & Cockburn, John & Martin, Will, 2010. "Would Freeing Up World Trade Reduce Poverty and Inequality? The Vexed Role of Agricultural Distortions," CEPR Discussion Papers 7749, C.E.P.R. Discussion Papers.
  19. De Gorter, Harry & Swinnen, Johan, 2002. "Political economy of agricultural policy," Handbook of Agricultural Economics, in: B. L. Gardner & G. C. Rausser (ed.), Handbook of Agricultural Economics, edition 1, volume 2, chapter 36, pages 1893-1943 Elsevier.
  20. Goyal, Aparajita, 2010. "Information, direct access to farmers, andrural market performance in central India," Policy Research Working Paper Series 5315, The World Bank.
  21. Binswanger, Hans P. & Deininger, Klaus & Feder, Gershon, 1993. "Power, distortions, revolt, and reform in agricultural land relations," Policy Research Working Paper Series 1164, The World Bank.
  22. Laffont, Jean-Jacques & Matoussi, Mohamed Salah., 1988. "Moral Hazard, Financial Constraints and Sharecropping in El Oulja," Working Papers 667, California Institute of Technology, Division of the Humanities and Social Sciences.
  23. M.Ataman Aksoy & Francis Ng, 2013. "The Evolution of Agricultural Trade Flows," Working Papers 2013/2, Turkish Economic Association.
  24. Eduardo Engel & Ronald Fischer & Alexander Galetovic, 2007. "The Basic Public Finance of Public-Private Partnerships," NBER Working Papers 13284, National Bureau of Economic Research, Inc.
  25. Headey, Derek & Fan, Shenggen, 2008. "Anatomy of a crisis: The causes and consequences of surging food prices," IFPRI discussion papers 831, International Food Policy Research Institute (IFPRI).
  26. Carter, Michael R, 1986. "The Economics of Price Scissors: Comment," American Economic Review, American Economic Association, vol. 76(5), pages 1192-94, December.
  27. Srinivasan, P. V. & Jha, Shikha, 2001. "Liberalized trade and domestic price stability. The case of rice and wheat in India," Journal of Development Economics, Elsevier, vol. 65(2), pages 417-441, August.
  28. Mansuri, Ghazala & Rao, Vijayendra, 2004. "Community-based (and driven) development : A critical review," Policy Research Working Paper Series 3209, The World Bank.
  29. Maitreesh Ghatak & Sanchari Roy, 2007. "Land reform and agricultural productivity in India: a review of the evidence," Oxford Review of Economic Policy, Oxford University Press, vol. 23(2), pages 251-269, Summer.
  30. Otsuka, Keijiro & Chuma, Hiroyuki & Hayami, Yujiro, 1992. "Land and Labor Contracts in Agrarian Economies: Theories and Facts," Journal of Economic Literature, American Economic Association, vol. 30(4), pages 1965-2018, December.
  31. Tavneet Suri, 2009. "Selection and Comparative Advantage in Technology Adoption," NBER Working Papers 15346, National Bureau of Economic Research, Inc.
  32. Luc Christiaensen & Lionel Demery, 2007. "Down to Earth : Agriculture and Poverty Reduction in Africa," World Bank Publications, The World Bank, number 6624, October.
  33. Binswanger-Mkhize, Hans & McCalla, Alex F., 2010. "The Changing Context and Prospects for Agricultural and Rural Development in Africa," Handbook of Agricultural Economics, Elsevier.
  34. de Janvry, Alain & Finan, Frederico & Sadoulet, Elisabeth & Vakis, Renos, 2006. "Can conditional cash transfer programs serve as safety nets in keeping children at school and from working when exposed to shocks?," Journal of Development Economics, Elsevier, vol. 79(2), pages 349-373, April.
  35. Baffes, John & Haniotis, Tassos, 2010. "Placing the 2006/08 commodity price boom into perspective," Policy Research Working Paper Series 5371, The World Bank.
  36. Vivien Foster & Cecilia Briceno-Garmendia, 2010. "Africa's Infrastructure : A Time for Transformation," World Bank Publications, The World Bank, number 2692, October.
  37. Timothy Besley & Robin Burgess, 2000. "Land Reform, Poverty Reduction, And Growth: Evidence From India," The Quarterly Journal of Economics, MIT Press, vol. 115(2), pages 389-430, May.
  38. Reardon, Thomas, 1997. "Using evidence of household income diversification to inform study of the rural nonfarm labor market in Africa," World Development, Elsevier, vol. 25(5), pages 735-747, May.
  39. Jonathan Kydd & Andrew Dorward, 2006. "Implications of Market and Coordination Failures for Rural Development in Least Developed Countries," Working Papers id:762, eSocialSciences.
  40. Diao, Xinshen & Hazell, Peter & Resnick, Danielle & Thurlow, James, 2006. "The role of agriculture in development: implications for Sub-Saharan Africa," DSGD discussion papers 29, International Food Policy Research Institute (IFPRI).
  41. Lanjouw, Jean O. & Lanjouw, Peter, 1995. "Rural nonfarm employment : a survey," Policy Research Working Paper Series 1463, The World Bank.
  42. Adelman, Irma, 1984. "Beyond export-led growth," World Development, Elsevier, vol. 12(9), pages 937-949, September.
  43. Azariadis, Costas & Stachurski, John, 2005. "Poverty Traps," Handbook of Economic Growth, in: Philippe Aghion & Steven Durlauf (ed.), Handbook of Economic Growth, edition 1, volume 1, chapter 5 Elsevier.
  44. Anderson, Jock R. & Feder, Gershon, 2007. "Agricultural Extension," Handbook of Agricultural Economics, Elsevier.
  45. Svetlana Edmeades & Melinda Smale, 2006. "A trait-based model of the potential demand for a genetically engineered food crop in a developing economy," Agricultural Economics, International Association of Agricultural Economists, vol. 35(3), pages 351-361, November.
  46. Wodon, Quentin & Zaman, Hassan, 2008. "Rising food prices in Sub-Saharan Africa : poverty impact and policy responses," Policy Research Working Paper Series 4738, The World Bank.
  47. Christopher B. Barrett & Michael R. Carter & C. Peter Timmer, 2010. "A Century-Long Perspective on Agricultural Development," American Journal of Agricultural Economics, Agricultural and Applied Economics Association, vol. 92(2), pages 447-468.
  48. Gonzales, Leonardo A. & Kasryno, Faisal & Perez, Nicostrato D. & Rosegrant, Mark W., 1993. "Economic incentives and comparative advantage in Indonesian food crop production:," Research reports 93, International Food Policy Research Institute (IFPRI).
  49. Adelman, Irma, 1984. "Beyond export-led growth," CUDARE Working Paper Series 309, University of California at Berkeley, Department of Agricultural and Resource Economics and Policy.
  50. Will Martin & Kym Anderson, 2006. "Agricultural Trade Reform and the Doha Development Agenda," World Bank Publications, The World Bank, number 6889, October.
  51. Kiminori Matsuyama, 1991. "Agricultural Productivity, Comparative Advantage and Economic Growth," NBER Working Papers 3606, National Bureau of Economic Research, Inc.
  52. Loayza, Norman V. & Raddatz, Claudio, 2006. "The composition of growth matters for poverty alleviation," Policy Research Working Paper Series 4077, The World Bank.
  53. Christiaensen, Luc & Demery, Lionel & Kuhl, Jesper, 2011. "The (evolving) role of agriculture in poverty reduction--An empirical perspective," Journal of Development Economics, Elsevier, vol. 96(2), pages 239-254, November.
  54. Lanjouw, Peter, 2001. "Nonfarm Employment and Poverty in Rural El Salvador," World Development, Elsevier, vol. 29(3), pages 529-547, March.
  55. Elisabeth Sadoulet & Alain de Janvry, 2009. "Agriculture for Development: Lessons from the World Development Report 2008," QA - Rivista dell'Associazione Rossi-Doria, Associazione Rossi Doria, issue 1, March.
  56. Chavas, Jean-Paul, 2001. "Structural change in agricultural production: Economics, technology and policy," Handbook of Agricultural Economics, in: B. L. Gardner & G. C. Rausser (ed.), Handbook of Agricultural Economics, edition 1, volume 1, chapter 5, pages 263-285 Elsevier.
  57. Savadogo, Kimseyinga & Reardon, Thomas & Pietola, Kyosti, 1998. "Adoption of improved land use technologies to increase food security in Burkina Faso: relating animal traction, productivity, and non-farm income," Agricultural Systems, Elsevier, vol. 58(3), pages 441-464, November.
  58. Maros Ivanic & Will Martin, 2008. "Implications of higher global food prices for poverty in low-income countries-super-1," Agricultural Economics, International Association of Agricultural Economists, vol. 39(s1), pages 405-416, November.
  59. Hazell, Peter & Poulton, Colin & Wiggins, Steve & Dorward, Andrew, 2010. "The Future of Small Farms: Trajectories and Policy Priorities," World Development, Elsevier, vol. 38(10), pages 1349-1361, October.
  60. Andre Croppenstedt & Mulat Demeke & Meloria M. Meschi, 2003. "Technology Adoption in the Presence of Constraints: the Case of Fertilizer Demand in Ethiopia," Review of Development Economics, Wiley Blackwell, vol. 7(1), pages 58-70, February.
  61. Ruttan, Vernon W., 2002. "Productivity Growth In World Agriculture: Sources And Constraints," Staff Papers 14176, University of Minnesota, Department of Applied Economics.
  62. von Braun, Joachim & Torero, Maximo, 2009. "Implementing physical and virtual food reserves to protect the poor and prevent market failure:," Policy briefs 10, International Food Policy Research Institute (IFPRI).
  63. Eicher, Carl K. & Maredia, Karim & Sithole-Niang, Idah, 2006. "Crop biotechnology and the African farmer," Food Policy, Elsevier, vol. 31(6), pages 504-527, December.
  64. Richard Tiffin & Xavier Irz, 2006. "Is agriculture the engine of growth?," Agricultural Economics, International Association of Agricultural Economists, vol. 35(1), pages 79-89, 07.
  65. Gaurav Datt & Martin Ravallion, 1998. "Farm productivity and rural poverty in India," Journal of Development Studies, Taylor & Francis Journals, vol. 34(4), pages 62-85.
  66. Mitchell, Donald, 2008. "A note on rising food prices," Policy Research Working Paper Series 4682, The World Bank.
  67. Stefan Dercon, 2009. "Rural Poverty: Old Challenges in New Contexts," World Bank Research Observer, World Bank Group, vol. 24(1), pages 1-28, April.
  68. Lanjouw, Jean O. & Lanjouw, Peter, 2001. "The rural non-farm sector: issues and evidence from developing countries," Agricultural Economics, Blackwell, vol. 26(1), pages 1-23, October.
  69. Barrett, Christopher B., 2002. "Food security and food assistance programs," Handbook of Agricultural Economics, in: B. L. Gardner & G. C. Rausser (ed.), Handbook of Agricultural Economics, edition 1, volume 2, chapter 40, pages 2103-2190 Elsevier.
  70. Gollin, Douglas, 2010. "Agricultural Productivity and Economic Growth," Handbook of Agricultural Economics, Elsevier.
  71. Valenzuela, Ernesto & van der Mensbrugghe, Dominique & Anderson, Kym, 2008. "General equilibrium effects of price distortions on global markets, farm incomes and welfare," Agricultural Distortions Working Paper 48630, World Bank.
  72. Ivanic, Maros & Martin, Will, 2008. "Implications of higher global food prices for poverty in low-income countries," Policy Research Working Paper Series 4594, The World Bank.
  73. Reardon, Thomas & Barrett, Christopher B. & Berdegué, Julio A. & Swinnen, Johan F.M., 2009. "Agrifood Industry Transformation and Small Farmers in Developing Countries," World Development, Elsevier, vol. 37(11), pages 1717-1727, November.
  74. Kym Anderson & Will Martin, 2009. "Distortions to Agricultural Incentives in Asia," World Bank Publications, The World Bank, number 2611, October.
  75. Pardey, Philip G. & James, Jennifer S. & Alston, Julian M. & Wood, Stanley & Koo, Bonwoo & Binenbaum, Eran & Hurley, Terrance M. & Glewwe, Paul & Mayer, Jorge & Jones, Richard & De Groote, Hugo & Kana, 2007. "Science, Technology and Skills," Reports 136256, University of Minnesota, International Science and Technology Practice and Policy.
  76. Paswel P. Marenya & Christopher B. Barrett, 2009. "State-conditional Fertilizer Yield Response on Western Kenyan Farms," American Journal of Agricultural Economics, Agricultural and Applied Economics Association, vol. 91(4), pages 991-1006.
  77. Mundlak, Yair & Larson, Donald F, 1992. "On the Transmission of World Agricultural Prices," World Bank Economic Review, World Bank Group, vol. 6(3), pages 399-422, September.
  78. Lanjouw, Peter & Ravallion, Martin, 1999. "Benefit Incidence, Public Spending Reforms, and the Timing of Program Capture," World Bank Economic Review, World Bank Group, vol. 13(2), pages 257-73, May.
  79. Brian D. Wright, 2012. "International Grain Reserves And Other Instruments to Address Volatility in Grain Markets," World Bank Research Observer, World Bank Group, vol. 27(2), pages 222-260, August.
  80. Bravo-Ortega, Claudio & Lederman, Daniel, 2005. "Agriculture and national welfare around the world: causality and international heterogeneity since 1960," Policy Research Working Paper Series 3499, The World Bank.
  81. Himanshu Himanshu & Peter Lanjouw & Abhiroop Mukhopadhyay & Rinku Murgai, 2011. "Non-farm diversification and rural poverty decline: a perspective from Indian sample survey and village study data," LSE Research Online Documents on Economics 38371, London School of Economics and Political Science, LSE Library.
  82. repec:fth:stanho:e-92-3 is not listed on IDEAS
  83. Raaj Kumar Sah & Joseph E. Stiglitz, 1984. "The Economics of Price Scissors," NBER Working Papers 1156, National Bureau of Economic Research, Inc.
  84. Sharmistha Self & Richard Grabowski, 2007. "Economic development and the role of agricultural technology," Agricultural Economics, International Association of Agricultural Economists, vol. 36(3), pages 395-404, 05.
  85. Nicholas Stern & Jean-Jacques Dethier & F. Halsey Rogers, 2006. "Growth and Empowerment: Making Development Happen," MIT Press Books, The MIT Press, edition 1, volume 1, number 0262693461, December.
  86. Eswaran, Mukesh & Kotwal, Ashok, 1993. "Export led development Primary vs. industrial exports," Journal of Development Economics, Elsevier, vol. 41(1), pages 163-172, June.
  87. Douglas Gollin & Michael Morris & Derek Byerlee, 2005. "Technology Adoption in Intensive Post-Green Revolution Systems," American Journal of Agricultural Economics, Agricultural and Applied Economics Association, vol. 87(5), pages 1310-1316.
  88. Ravallion, Martin & Datt, Gaurav, 1996. "How Important to India's Poor Is the Sectoral Composition of Economic Growth?," World Bank Economic Review, World Bank Group, vol. 10(1), pages 1-25, January.
  89. Jenny C. Aker, 2010. "Information from Markets Near and Far: Mobile Phones and Agricultural Markets in Niger," American Economic Journal: Applied Economics, American Economic Association, vol. 2(3), pages 46-59, July.
  90. Matsumoto, Tomoya & Yamano, Takashi, 2009. "Soil fertility, fertilizer, and the maize green revolution in East Africa," Policy Research Working Paper Series 5158, The World Bank.
  91. Timmer, C. Peter, 2002. "Agriculture and economic development," Handbook of Agricultural Economics, in: B. L. Gardner & G. C. Rausser (ed.), Handbook of Agricultural Economics, edition 1, volume 2, chapter 29, pages 1487-1546 Elsevier.
  92. David Coady & Margaret Grosh & John Hoddinott, 2004. "Targeting of Transfers in Developing Countries : Review of Lessons and Experience," World Bank Publications, The World Bank, number 14902, October.
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  1. Food Price Index, 1970 - 2010
    by UDADISI in UDADISI on 2012-09-23 22:53:00
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  2. Okoboi, Godfrey & Barungi, Mildred, 2012. "Constraints to Fertiliser Use in Uganda: Insights from Uganda Census of Agriculture 2008/9," Research Series 150240, Economic Policy Research Centre (EPRC).
  3. Raza, Syed Ali & Ali, Yasir & Mehboob, Farhan, 2012. "Role of agriculture in economic growth of Pakistan," MPRA Paper 32273, University Library of Munich, Germany, revised Jan 2012.
  4. Allen, Summer L. & Badiane, Ousmane & Ulimwengu, John M., 2012. "Government Expenditures, Social Outcomes, and Marginal Productivity of Agricultural Inputs: A Case Study for Tanzania," 2012 Conference, August 18-24, 2012, Foz do Iguacu, Brazil 126663, International Association of Agricultural Economists.
  5. Girard, Alexandra M., 2014. "Stepping into Formal Politics," World Development, Elsevier, vol. 57(C), pages 1-18.
  6. Han-Hsin Chang & Charles van Marrewijk & Randy Stringer & Wendy Umberger, 2013. "Investment, awareness, supermarkets, and profits: heterogeneous chili farmers in Indonesia," Working Papers 13-13, Utrecht School of Economics.

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