IDEAS home Printed from https://ideas.repec.org/p/nbr/nberwo/19233.html
   My bibliography  Save this paper

The Cognitive Effects of Micronutrient Deficiency: Evidence from Salt Iodization in the United States

Author

Listed:
  • James Feyrer
  • Dimitra Politi
  • David N. Weil

Abstract

Iodine deficiency is the leading cause of preventable mental retardation in the world today. The condition, which was common in the developed world until the introduction of iodized salt in the 1920s, is connected to low iodine levels in the soil and water. We examine the impact of salt iodization on cognitive outcomes in the US by taking advantage of this natural geographic variation. Salt was iodized over a very short period of time beginning in 1924. We use military data collected during WWI and WWII to compare outcomes of cohorts born before and after iodization, in localities that were naturally poor and rich in iodine. We find that for the one quarter of the population most deficient in iodine this intervention raised IQ by approximately one standard deviation. Our results can explain roughly one decade's worth of the upwardtrend in IQ in the US (the Flynn Effect). We also document a large increase in thyroid related deaths following the countrywide adoption of iodized salt, which affected mostly older individuals in localities with high prevalence of iodine deficiency.

Suggested Citation

  • James Feyrer & Dimitra Politi & David N. Weil, 2013. "The Cognitive Effects of Micronutrient Deficiency: Evidence from Salt Iodization in the United States," NBER Working Papers 19233, National Bureau of Economic Research, Inc.
  • Handle: RePEc:nbr:nberwo:19233
    Note: CH DAE DEV EFG HE
    as

    Download full text from publisher

    File URL: http://www.nber.org/papers/w19233.pdf
    Download Restriction: no
    ---><---

    Other versions of this item:

    References listed on IDEAS

    as
    1. Bishai, David & Nalubola, Ritu, 2002. "The History of Food Fortification in the United States: Its Relevance for Current Fortification Efforts in Developing Countries," Economic Development and Cultural Change, University of Chicago Press, vol. 51(1), pages 37-53, October.
    2. Erica Field & Omar Robles & Maximo Torero, 2009. "Iodine Deficiency and Schooling Attainment in Tanzania," American Economic Journal: Applied Economics, American Economic Association, vol. 1(4), pages 140-169, October.
    3. Politi, Dimitra, 2010. "The Impact of Iodine Deficiency Eradication on Schooling: Evidence from the Introduction of Iodized Salt in Switzerland," SIRE Discussion Papers 2010-02, Scottish Institute for Research in Economics (SIRE).
    4. Watson, Tara, 2006. "Public health investments and the infant mortality gap: Evidence from federal sanitation interventions on U.S. Indian reservations," Journal of Public Economics, Elsevier, vol. 90(8-9), pages 1537-1560, September.
    5. Markel, H., 1987. "'When it rains it pours': Endemic goiter, iodized salt, and David Murray Cowie, MD," American Journal of Public Health, American Public Health Association, vol. 77(2), pages 219-229.
    6. Hoyt Bleakley, 2007. "Disease and Development: Evidence from Hookworm Eradication in the American South," The Quarterly Journal of Economics, Oxford University Press, vol. 122(1), pages 73-117.
    Full references (including those not matched with items on IDEAS)

    Citations

    Blog mentions

    As found by EconAcademics.org, the blog aggregator for Economics research:
    1. Dr. Joel Fuhrman Sells Useless Iodine Test
      by ? in Science-Based Medicine on 2018-03-27 07:00:10

    Citations

    Citations are extracted by the CitEc Project, subscribe to its RSS feed for this item.
    as


    Cited by:

    1. Douglas Almond & Janet Currie & Valentina Duque, 2018. "Childhood Circumstances and Adult Outcomes: Act II," Journal of Economic Literature, American Economic Association, vol. 56(4), pages 1360-1446, December.
    2. Massimiliano Giacalone & Agata Zirilli & Mariacarla Moleti & Angela Alibrandi, 2018. "Does the iodized salt therapy of pregnant mothers increase the children IQ? Empirical evidence of a statistical study based on permutation tests," Quality & Quantity: International Journal of Methodology, Springer, vol. 52(3), pages 1423-1435, May.
    3. Lazuka, Volha, 2017. "The lasting health and income effects of public health formation in Sweden," Lund Papers in Economic History 153, Lund University, Department of Economic History.
    4. Alex-Petersen, Jesper & Lundborg, Petter & Rooth, Dan-Olof, 2017. "Long-Term Effects of Childhood Nutrition: Evidence from a School Lunch Reform," IZA Discussion Papers 11234, Institute of Labor Economics (IZA).
    5. Leandro De Magalhães & Dongya Koh & Raül Santaeulàlia-Llopis, 2016. "Consumption and Expenditure in Sub-Saharan Africa," Bristol Economics Discussion Papers 16/677, School of Economics, University of Bristol, UK, revised 07 Oct 2016.
    6. Deng, Zichen & Lindeboom, Maarten, 2019. "A Bit of Salt, a Trace of Life: Gender Norms and the Impact of a Salt Iodization Program on Human Capital Formation of School Aged Children," IZA Discussion Papers 12629, Institute of Labor Economics (IZA).
    7. Niklas Bengtsson & Fredrik Sävje & Stefan Swartling Peterson, 2020. "Fetal Iodine Deficiency and Schooling: A Replication of Field, Robles, and Torero (2009)," Scandinavian Journal of Economics, Wiley Blackwell, vol. 122(2), pages 582-621, April.
    8. Clay, Karen & Schmick, Ethan & Troesken, Werner, 2019. "The Rise and Fall of Pellagra in the American South," The Journal of Economic History, Cambridge University Press, vol. 79(1), pages 32-62, March.
    9. David B. Audretsch, 2015. "Knowledge spillovers and future jobs," IZA World of Labor, Institute of Labor Economics (IZA), pages 218-218, December.
    10. Morgan Kelly & Joel Mokyr & Cormac Ó Gráda, 2014. "Precocious Albion: A New Interpretation of the British Industrial Revolution," Annual Review of Economics, Annual Reviews, vol. 6(1), pages 363-389, August.
    11. Achyuta Adhvaryu & Steven Bednar & Teresa Molina & Quynh Nguyen & Anant Nyshadham, 2020. "When It Rains It Pours: The Long-Run Economic Impacts of Salt Iodization in the United States," The Review of Economics and Statistics, MIT Press, vol. 102(2), pages 395-407, May.
    12. Bolbocean, Corneliu & Tylavsky, Frances A., 2021. "The impact of safety net programs on early-life developmental outcomes," Food Policy, Elsevier, vol. 100(C).
    13. Victor Lavy & Analia Schlosser & Adi Shany, 2016. "Out of Africa: Human Capital Consequences of In Utero Conditions," NBER Working Papers 21894, National Bureau of Economic Research, Inc.
    14. Tafesse, W.;, 2018. "The effect of mandatory iodine fortification on cognitive test scores in rural India," Health, Econometrics and Data Group (HEDG) Working Papers 18/10, HEDG, c/o Department of Economics, University of York.
    15. Daniel Herrera‐Araujo, 2016. "Folic acid advisories: a public health challenge?," Health Economics, John Wiley & Sons, Ltd., vol. 25(9), pages 1104-1122, September.
    16. Leandro DE MAGALHÃES & Dongya KOH & Räul SANTAEULILA-LLOPIS, 2019. "The Cost of Consumption Smoothing: Less Schooling and less Nutrition," JODE - Journal of Demographic Economics, Cambridge University Press, vol. 85(3), pages 181-208, September.
    17. N. Meltem Daysal, 2015. "Early-life medical care and human capital accumulation," IZA World of Labor, Institute of Labor Economics (IZA), pages 218-218, December.
    18. Zichen Deng & Maarten Lindeboom, 2020. "A Bit of Salt a Trace of Life - Gender Norms and The Impact of a Salt Iodization Program on Human Capital Formation of School Aged Children," Tinbergen Institute Discussion Papers 20-067/V, Tinbergen Institute.
    19. Matthew Lee & Arzi Adbi & Jasjit Singh, 2020. "Categorical cognition and outcome efficiency in impact investing decisions," Strategic Management Journal, Wiley Blackwell, vol. 41(1), pages 86-107, January.
    20. Huang, Qingyang & Liu, Chang & Zhou, Li-An, 2020. "Farewell to the God of Plague: Estimating the effects of China's Universal Salt Iodization on educational outcomes," Journal of Comparative Economics, Elsevier, vol. 48(1), pages 20-36.
    21. Gregory T. Niemesh, 2015. "Ironing Out Deficiencies: Evidence from the United States on the Economic Effects of Iron Deficiency," Journal of Human Resources, University of Wisconsin Press, vol. 50(4), pages 910-958.

    Most related items

    These are the items that most often cite the same works as this one and are cited by the same works as this one.
    1. Feyrer, James & Politi, Dimitra & Weil, David N., 2010. "The Economic Effects of Micronutrient Deficiency: Evidence from Salt Iodization in the United States," SIRE Discussion Papers 2010-10, Scottish Institute for Research in Economics (SIRE).
    2. Achyuta Adhvaryu & Steven Bednar & Teresa Molina & Quynh Nguyen & Anant Nyshadham, 2020. "When It Rains It Pours: The Long-Run Economic Impacts of Salt Iodization in the United States," The Review of Economics and Statistics, MIT Press, vol. 102(2), pages 395-407, May.
    3. Tafesse, W.;, 2018. "The effect of mandatory iodine fortification on cognitive test scores in rural India," Health, Econometrics and Data Group (HEDG) Working Papers 18/10, HEDG, c/o Department of Economics, University of York.
    4. Yu-Fu Chen & Gylfi Zoega, 2010. "Strong Hysteresis due to Age Effects," Dundee Discussion Papers in Economics 230, Economic Studies, University of Dundee.
    5. Michael Geruso & Dean Spears, 2018. "Neighborhood Sanitation and Infant Mortality," American Economic Journal: Applied Economics, American Economic Association, vol. 10(2), pages 125-162, April.
    6. Bloom, David E. & Canning, David & Kotschy, Rainer & Prettner, Klaus & Schünemann, Johannes, 2018. "Health and Economic Growth: Reconciling the Micro and Macro Evidence," IZA Discussion Papers 11940, Institute of Labor Economics (IZA).
    7. Pierre-Richard Agénor, 2018. "Health and Knowledge Externalities: Implications for Growth and Public Policy ," Centre for Growth and Business Cycle Research Discussion Paper Series 245, Economics, The University of Manchester.
    8. Douglas Almond & Janet Currie, 2011. "Killing Me Softly: The Fetal Origins Hypothesis," Journal of Economic Perspectives, American Economic Association, vol. 25(3), pages 153-172, Summer.
    9. David E Bloom & Michael Kuhn & Klaus Prettner, 2020. "The contribution of female health to economic development [The costs of missing the Millennium Development Goal on gender equity]," Economic Journal, Royal Economic Society, vol. 130(630), pages 1650-1677.
    10. Franck, Raphaã‹L & Rainer, Ilia, 2012. "Does the Leader's Ethnicity Matter? Ethnic Favoritism, Education, and Health in Sub-Saharan Africa," American Political Science Review, Cambridge University Press, vol. 106(2), pages 294-325, May.
    11. Payal Hathi & Sabrina Haque & Lovey Pant & Diane Coffey & Dean Spears, 2017. "Place and Child Health: The Interaction of Population Density and Sanitation in Developing Countries," Demography, Springer;Population Association of America (PAA), vol. 54(1), pages 337-360, February.
    12. David E. BLOOM & Michael KUHN & Klaus PRETTNER, 2017. "Africa’s Prospects for Enjoying a Demographic Dividend," JODE - Journal of Demographic Economics, Cambridge University Press, vol. 83(1), pages 63-76, March.
    13. Zhang, Jing, 2012. "The impact of water quality on health: Evidence from the drinking water infrastructure program in rural China," Journal of Health Economics, Elsevier, vol. 31(1), pages 122-134.
    14. Douglas Almond & Janet Currie & Valentina Duque, 2018. "Childhood Circumstances and Adult Outcomes: Act II," Journal of Economic Literature, American Economic Association, vol. 56(4), pages 1360-1446, December.
    15. Fung, Winnie & Robles, Omar, 2016. "Effects of antenatal testing laws on infant mortality," Journal of Health Economics, Elsevier, vol. 45(C), pages 77-90.
    16. Wang, Qing & Zhang, Shiying, 2020. "Gender Inequality in Nutrition Intake: Evidence from a Large Assistance Program," GLO Discussion Paper Series 740, Global Labor Organization (GLO).
    17. Hoque, Mohammad Mainul & King, Elizabeth M. & Montenegro, Claudio E. & Orazem, Peter F., 2020. "Life Expectancy at Birth and Lifetime Education and Earnings," ISU General Staff Papers 202009010700001121, Iowa State University, Department of Economics.
    18. Orazio Attanasio & Costas Meghir & Emily Nix, 2015. "Human Capital Development and Parental Investment in India," Cowles Foundation Discussion Papers 2026R2, Cowles Foundation for Research in Economics, Yale University, revised Apr 2019.
    19. Orgill-Meyer, Jennifer & Pattanayak, Subhrendu K., 2020. "Improved sanitation increases long-term cognitive test scores," World Development, Elsevier, vol. 132(C).
    20. Schady, Norbert, 2015. "Does Access to Better Water and Sanitation Infrastructure Improve Child Outcomes? Evidence from Latin America and the Caribbean," IDB Publications (Working Papers) 7369, Inter-American Development Bank.

    More about this item

    JEL classification:

    • I18 - Health, Education, and Welfare - - Health - - - Government Policy; Regulation; Public Health
    • I28 - Health, Education, and Welfare - - Education - - - Government Policy
    • J24 - Labor and Demographic Economics - - Demand and Supply of Labor - - - Human Capital; Skills; Occupational Choice; Labor Productivity
    • N32 - Economic History - - Labor and Consumers, Demography, Education, Health, Welfare, Income, Wealth, Religion, and Philanthropy - - - U.S.; Canada: 1913-

    NEP fields

    This paper has been announced in the following NEP Reports:

    Statistics

    Access and download statistics

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:nbr:nberwo:19233. See general information about how to correct material in RePEc.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: . General contact details of provider: https://edirc.repec.org/data/nberrus.html .

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a bibliographic reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (email available below). General contact details of provider: https://edirc.repec.org/data/nberrus.html .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service hosted by the Research Division of the Federal Reserve Bank of St. Louis . RePEc uses bibliographic data supplied by the respective publishers.