IDEAS home Printed from https://ideas.repec.org/p/feb/natura/00720.html
   My bibliography  Save this paper

The Value of Time in the United States: Estimates from Nationwide Natural Field Experiments

Author

Listed:
  • Ariel Goldszmidt
  • John List
  • Robert Metcalfe
  • Ian Muir
  • Jenny Wang

Abstract

The value of time determines relative prices of goods and services, investments, productivity, economic growth, and measures of income inequality. Economists in the 1960s began to focus on the value of non-work time, pioneering a deep literature exploring the optimal allocation and value of time. By leveraging key features of these classic time allocation theories, we use a novel approach to estimate the value of time (VOT) via two large-scale natural field experiments with the ridesharing company Lyft. We use random variation in both wait times and prices to estimate a consumer's VOT with a data set of more than 14 million observations across consumers in US cities. We find that the VOT is roughly $19 per hour (or 75% (100%) of the after-tax mean (median) wage rate) and varies predictably with choice circumstances correlated with the opportunity cost of wait time. Our VOT estimate is larger than what is currently used by the US Government, suggesting that society is under-valuing time improvements and subsequently under-investing public resources in time-saving infrastructure projects and technologies.

Suggested Citation

  • Ariel Goldszmidt & John List & Robert Metcalfe & Ian Muir & Jenny Wang, 2020. "The Value of Time in the United States: Estimates from Nationwide Natural Field Experiments," Natural Field Experiments 00720, The Field Experiments Website.
    • Handle: RePEc:feb:natura:00720
    as

    Download full text from publisher

    File URL: http://s3.amazonaws.com/fieldexperiments-papers2/papers/00720.pdf
    Download Restriction: no
    ---><---

    Other versions of this item:

    References listed on IDEAS

    as
    1. Bruno Crépon & Esther Duflo & Marc Gurgand & Roland Rathelot & Philippe Zamora, 2013. "Do Labor Market Policies have Displacement Effects? Evidence from a Clustered Randomized Experiment," The Quarterly Journal of Economics, Oxford University Press, vol. 128(2), pages 531-580.
    2. Kastl, Jakub & Buchholz, Nicholas & Doval, Laura & Matějka, Filip & Salz, Tobias, 2020. "The Value of Time: Evidence From Auctioned Cab Rides," CEPR Discussion Papers 14666, C.E.P.R. Discussion Papers.
    3. Christopher F Baum & Mark E. Schaffer & Steven Stillman, 2003. "Instrumental variables and GMM: Estimation and testing," Stata Journal, StataCorp LP, vol. 3(1), pages 1-31, March.
    4. Jonathan D Hall, 0. "Can Tolling Help Everyone? Estimating the Aggregate and Distributional Consequences of Congestion Pricing," Journal of the European Economic Association, European Economic Association, vol. 19(1), pages 441-474.
    5. Grant Miller & B. Piedad Urdinola, 2010. "Cyclicality, Mortality, and the Value of Time: The Case of Coffee Price Fluctuations and Child Survival in Colombia," Journal of Political Economy, University of Chicago Press, vol. 118(1), pages 113-155, February.
    6. Stefano DellaVigna & John A. List & Ulrike Malmendier, 2012. "Testing for Altruism and Social Pressure in Charitable Giving," The Quarterly Journal of Economics, Oxford University Press, vol. 127(1), pages 1-56.
    7. Mill, John Stuart, 1848. "Principles of Political Economy (II): Distribution," History of Economic Thought Books, McMaster University Archive for the History of Economic Thought, volume 2, number mill1848-2.
    8. Kleibergen, Frank & Paap, Richard, 2006. "Generalized reduced rank tests using the singular value decomposition," Journal of Econometrics, Elsevier, vol. 133(1), pages 97-126, July.
    9. Benhabib, Jess & Rogerson, Richard & Wright, Randall, 1991. "Homework in Macroeconomics: Household Production and Aggregate Fluctuations," Journal of Political Economy, University of Chicago Press, vol. 99(6), pages 1166-1187, December.
    10. Valerie A. Ramey & Neville Francis, 2009. "A Century of Work and Leisure," American Economic Journal: Macroeconomics, American Economic Association, vol. 1(2), pages 189-224, July.
    11. Hainmueller, Jens, 2012. "Entropy Balancing for Causal Effects: A Multivariate Reweighting Method to Produce Balanced Samples in Observational Studies," Political Analysis, Cambridge University Press, vol. 20(1), pages 25-46, January.
    12. Ian W. H. Parry & Kenneth A. Small, 2009. "Should Urban Transit Subsidies Be Reduced?," American Economic Review, American Economic Association, vol. 99(3), pages 700-724, June.
    13. Aviv Nevo & Arlene Wong, 2019. "The Elasticity Of Substitution Between Time And Market Goods: Evidence From The Great Recession," International Economic Review, Department of Economics, University of Pennsylvania and Osaka University Institute of Social and Economic Research Association, vol. 60(1), pages 25-51, February.
    14. Glenn W. Harrison & John A. List, 2004. "Field Experiments," Journal of Economic Literature, American Economic Association, vol. 42(4), pages 1009-1055, December.
    15. Jeremy Greenwood & Nezih Guner & Guillaume Vandenbroucke, 2017. "Family Economics Writ Large," Journal of Economic Literature, American Economic Association, vol. 55(4), pages 1346-1434, December.
    16. Leonardo J. Basso & Hugo E. Silva, 2014. "Efficiency and Substitutability of Transit Subsidies and Other Urban Transport Policies," American Economic Journal: Economic Policy, American Economic Association, vol. 6(4), pages 1-33, November.
    17. Michael L. Anderson, 2014. "Subways, Strikes, and Slowdowns: The Impacts of Public Transit on Traffic Congestion," American Economic Review, American Economic Association, vol. 104(9), pages 2763-2796, September.
    18. Tomas J. Philipson & Gary Becker & Dana Goldman & Kevin M. Murphy, 2010. "Terminal Care and The Value of Life Near Its End," NBER Working Papers 15649, National Bureau of Economic Research, Inc.
    19. Gilles Duranton & Matthew A. Turner, 2011. "The Fundamental Law of Road Congestion: Evidence from US Cities," American Economic Review, American Economic Association, vol. 101(6), pages 2616-2652, October.
    20. Alexandre Mas & Amanda Pallais, 2019. "Labor Supply and the Value of Non-work Time: Experimental Estimates from the Field," American Economic Review: Insights, American Economic Association, vol. 1(1), pages 111-126, June.
    21. Gilbert Ghez & Gary S. Becker, 1975. "The Allocation of Time and Goods over the Life Cycle," NBER Books, National Bureau of Economic Research, Inc, number ghez75-1, June.
    22. Alexandre Mas & Amanda Pallais, 2017. "Valuing Alternative Work Arrangements," American Economic Review, American Economic Association, vol. 107(12), pages 3722-3759, December.
    23. John A. List, 2020. "Non est Disputandum de Generalizability? A Glimpse into The External Validity Trial," NBER Working Papers 27535, National Bureau of Economic Research, Inc.
    24. Mill, John Stuart, 1848. "Principles of Political Economy (III): Exchange," History of Economic Thought Books, McMaster University Archive for the History of Economic Thought, volume 3, number mill1848-3.
    25. Smith, V. Kerry & Banzhaf, H. Spencer, 2007. "Quality adjusted price indexes and the Willig condition," Economics Letters, Elsevier, vol. 94(1), pages 43-48, January.
    26. Martin Browning & Thomas F. Crossley & Joachim Winter, 2014. "The Measurement of Household Consumption Expenditures," Annual Review of Economics, Annual Reviews, vol. 6(1), pages 475-501, August.
    27. Claudia Goldin, 2014. "A Grand Gender Convergence: Its Last Chapter," American Economic Review, American Economic Association, vol. 104(4), pages 1091-1119, April.
    28. Hunt Allcott & Luca Braghieri & Sarah Eichmeyer & Matthew Gentzkow, 2020. "The Welfare Effects of Social Media," American Economic Review, American Economic Association, vol. 110(3), pages 629-676, March.
    29. Juster, F Thomas & Stafford, Frank P, 1991. "The Allocation of Time: Empirical Findings, Behavioral Models, and Problems of Measurement," Journal of Economic Literature, American Economic Association, vol. 29(2), pages 471-522, June.
    30. Alan B. Krueger, 2009. "Measuring the Subjective Well-Being of Nations: National Accounts of Time Use and Well-Being," NBER Books, National Bureau of Economic Research, Inc, number krue08-1, June.
    31. Austan Goolsbee & Peter J. Klenow, 2006. "Valuing Consumer Products by the Time Spent Using Them: An Application to the Internet," American Economic Review, American Economic Association, vol. 96(2), pages 108-113, May.
    32. Besley, Timothy & Hall, John & Preston, Ian, 1999. "The demand for private health insurance: do waiting lists matter?," Journal of Public Economics, Elsevier, vol. 72(2), pages 155-181, May.
    33. Gilbert Ghez & Gary S. Becker, 1975. "A Theory of the Allocation of Time and Goods Over the Life Cycle," NBER Chapters, in: The Allocation of Time and Goods over the Life Cycle, pages 1-45, National Bureau of Economic Research, Inc.
    34. Smith, V. Kerry & Mansfield, Carol, 1998. "Buying Time: Real and Hypothetical Offers," Journal of Environmental Economics and Management, Elsevier, vol. 36(3), pages 209-224, November.
    35. Alan B. Krueger & Daniel Kahneman & David Schkade & Norbert Schwarz & Arthur A. Stone, 2009. "National Time Accounting: The Currency of Life," NBER Chapters, in: Measuring the Subjective Well-Being of Nations: National Accounts of Time Use and Well-Being, pages 9-86, National Bureau of Economic Research, Inc.
    36. Mark Aguiar & Mark Bils & Kerwin Kofi Charles & Erik Hurst, 2021. "Leisure Luxuries and the Labor Supply of Young Men," Journal of Political Economy, University of Chicago Press, vol. 129(2), pages 337-382.
    37. A. Colin Cameron & Douglas L. Miller, 2015. "A Practitioner’s Guide to Cluster-Robust Inference," Journal of Human Resources, University of Wisconsin Press, vol. 50(2), pages 317-372.
    38. Krueger, Alan B. (ed.), 2009. "Measuring the Subjective Well-Being of Nations," University of Chicago Press Economics Books, University of Chicago Press, number 9780226454573, December.
    39. Amy Finkelstein, 2009. "E-ztax: Tax Salience and Tax Rates," The Quarterly Journal of Economics, Oxford University Press, vol. 124(3), pages 969-1010.
    40. Yan Chen & Grace Jeon & Yong-Mi Kim, 2014. "A day without a search engine: an experimental study of online and offline searches," Experimental Economics, Springer;Economic Science Association, vol. 17(4), pages 512-536, December.
    41. McFadden, Daniel, 1974. "The measurement of urban travel demand," Journal of Public Economics, Elsevier, vol. 3(4), pages 303-328, November.
    42. Arnott, Richard & de Palma, Andre & Lindsey, Robin, 1993. "A Structural Model of Peak-Period Congestion: A Traffic Bottleneck with Elastic Demand," American Economic Review, American Economic Association, vol. 83(1), pages 161-179, March.
    43. Van Ommeren, Jos & Fosgerau, Mogens, 2009. "Workers' marginal costs of commuting," Journal of Urban Economics, Elsevier, vol. 65(1), pages 38-47, January.
    44. Frank J. Cesario, 1976. "Value of Time in Recreation Benefit Studies," Land Economics, University of Wisconsin Press, vol. 52(1), pages 32-41.
    45. Mill, John Stuart, 1848. "Principles of Political Economy (I): Production," History of Economic Thought Books, McMaster University Archive for the History of Economic Thought, volume 1, number mill1848-1.
    46. Tomas J. Philipson & Gary Becker & Dana Goldman & Kevin M. Murphy, 2010. "Terminal Care and The Value of Life Near Its End," NBER Working Papers 15649, National Bureau of Economic Research, Inc.
    47. Deacon, Robert T & Sonstelie, Jon, 1985. "Rationing by Waiting and the Value of Time: Results from a Natural Experiment," Journal of Political Economy, University of Chicago Press, vol. 93(4), pages 627-647, August.
    48. Wheaton, William C, 1977. "Income and Urban Residence: An Analysis of Consumer Demand for Location," American Economic Review, American Economic Association, vol. 67(4), pages 620-631, September.
    49. David I. Green, 1894. "Pain-Cost and Opportunity-Cost," The Quarterly Journal of Economics, Oxford University Press, vol. 8(2), pages 218-229.
    50. Yihsu Chen & Alexander Whalley, 2012. "Green Infrastructure: The Effects of Urban Rail Transit on Air Quality," American Economic Journal: Economic Policy, American Economic Association, vol. 4(1), pages 58-97, February.
    51. Antonio Bento & Kevin Roth & Andrew R. Waxman, 2020. "Avoiding Traffic Congestion Externalities? The Value of Urgency," NBER Working Papers 26956, National Bureau of Economic Research, Inc.
    52. Kenneth A. Small & Clifford Winston & Jia Yan, 2005. "Uncovering the Distribution of Motorists' Preferences for Travel Time and Reliability," Econometrica, Econometric Society, vol. 73(4), pages 1367-1382, July.
    53. Heckman, James, 2013. "Sample selection bias as a specification error," Applied Econometrics, Russian Presidential Academy of National Economy and Public Administration (RANEPA), vol. 31(3), pages 129-137.
    54. Krueger, Alan B. (ed.), 2009. "Measuring the Subjective Well-Being of Nations," National Bureau of Economic Research Books, University of Chicago Press, number 9780226454566.
    55. Aguiar, M. & Hurst, E., 2016. "The Macroeconomics of Time Allocation," Handbook of Macroeconomics, in: J. B. Taylor & Harald Uhlig (ed.), Handbook of Macroeconomics, edition 1, volume 2, chapter 0, pages 203-253, Elsevier.
    56. Jonathan D Hall, 2021. "Can Tolling Help Everyone? Estimating the Aggregate and Distributional Consequences of Congestion Pricing," Journal of the European Economic Association, European Economic Association, vol. 19(1), pages 441-474.
    57. Gronau, Reuben, 1973. "The Intrafamily Allocation of Time: The Value of the Housewives' Time," American Economic Review, American Economic Association, vol. 63(4), pages 634-651, September.
    58. William Nordhaus, 2009. "Measuring Real Income with Leisure and Household Production," NBER Chapters, in: Measuring the Subjective Well-Being of Nations: National Accounts of Time Use and Well-Being, pages 125-144, National Bureau of Economic Research, Inc.
    59. Joshua D. Angrist & Kathryn Graddy & Guido W. Imbens, 2000. "The Interpretation of Instrumental Variables Estimators in Simultaneous Equations Models with an Application to the Demand for Fish," Review of Economic Studies, Oxford University Press, vol. 67(3), pages 499-527.
    60. DeSerpa, A C, 1971. "A Theory of the Economics of Time," Economic Journal, Royal Economic Society, vol. 81(324), pages 828-846, December.
    61. Mark Aguiar & Erik Hurst & Loukas Karabarbounis, 2013. "Time Use during the Great Recession," American Economic Review, American Economic Association, vol. 103(5), pages 1664-1696, August.
    62. Mill, John Stuart, 1848. "Principles of Political Economy (V): On the Influence of Government," History of Economic Thought Books, McMaster University Archive for the History of Economic Thought, volume 5, number mill1848-5.
    63. Gilbert Ghez & Gary S. Becker, 1975. "The Allocation of Goods Over the Life Cycle," NBER Chapters, in: The Allocation of Time and Goods over the Life Cycle, pages 46-82, National Bureau of Economic Research, Inc.
    64. repec:feb:framed:0087 is not listed on IDEAS
    65. Gilbert Ghez & Gary S. Becker, 1975. "The Allocation of Time Over the Life Cycle," NBER Chapters, in: The Allocation of Time and Goods over the Life Cycle, pages 83-132, National Bureau of Economic Research, Inc.
    66. Jeremy Greenwood & Nezih Guner & Guillaume Vandenbroucke, 2017. "Family Economics Writ Large," Working Papers wp2018_1706, CEMFI.
    67. Alexander M. Gelber & Joshua W. Mitchell, 2012. "Taxes and Time Allocation: Evidence from Single Women and Men," Review of Economic Studies, Oxford University Press, vol. 79(3), pages 863-897.
    68. Peter Cohen & Robert Hahn & Jonathan Hall & Steven Levitt & Robert Metcalfe, 2016. "Using Big Data to Estimate Consumer Surplus: The Case of Uber," NBER Working Papers 22627, National Bureau of Economic Research, Inc.
    Full references (including those not matched with items on IDEAS)

    Citations

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


    Cited by:

    1. Su, Yichen, 2022. "Measuring the Value of Urban Consumption Amenities: A Time-Use Approach," Journal of Urban Economics, Elsevier, vol. 132(C).
    2. Rossetti, Tomás & Broaddus, Andrea & Ruhl, Melissa & Daziano, Ricardo, 2023. "Commuter preferences for a first-mile/last-mile microtransit service in the United States," Transportation Research Part A: Policy and Practice, Elsevier, vol. 167(C).
    3. Dai, Peichao & Zhang, Shaoliang & Gong, Yunlong & Zhou, Yuan & Hou, Huping, 2022. "A crowd-sourced valuation of recreational ecosystem services using mobile signal data applied to a restored wetland in China," Ecological Economics, Elsevier, vol. 192(C).
    4. Krčál, Ondřej & Peer, Stefanie & Staněk, Rostislav, 2021. "Can time-inconsistent preferences explain hypothetical biases?," Economics of Transportation, Elsevier, vol. 25(C).
    5. Su, Yichen, 2022. "Measuring the Value of Urban Consumption Amenities: A Time-Use Approach," MPRA Paper 113158, University Library of Munich, Germany.
    6. Wichman, Casey J. & Cunningham, Brandon, 2023. "Notching for free: Do cyclists reveal the opportunity cost of time?," Journal of Environmental Economics and Management, Elsevier, vol. 119(C).
    7. Lam, Chungsang Tom & Liu, Meng & Hui, Xiang, 2021. "The geography of ridesharing: A case study on New York City," Information Economics and Policy, Elsevier, vol. 57(C).
    8. Xiaoxia Dong & Erick Guerra & Ricardo A. Daziano, 2022. "Impact of TNC on travel behavior and mode choice: a comparative analysis of Boston and Philadelphia," Transportation, Springer, vol. 49(6), pages 1577-1597, December.
    9. Christensen, Peter & Osman, Adam, 2021. "The Demand for Mobility: Evidence from an Experiment with Uber Riders," IZA Discussion Papers 14179, Institute of Labor Economics (IZA).
    10. Randriamaro, Mary Tiana & Cook, Joseph, 2022. "The value of time, with and without a smartphone," Journal of Economic Behavior & Organization, Elsevier, vol. 200(C), pages 138-146.
    11. Krekel, Christian & MacKerron, George, 2023. "Back to Edgeworth? Estimating the Value of Time Using Hedonic Experiences," IZA Discussion Papers 16308, Institute of Labor Economics (IZA).
    12. Hsiao, Yu-Chin & Kemp, Simon & Servátka, Maroš & Ward, Matt & Zhang, Le, 2021. "Time Costs and Search Behavior," MPRA Paper 105412, University Library of Munich, Germany.
    13. Durrmeyer, Isis & Martinez, Nicolas, 2022. "The Welfare Consequences of Urban Traffic Regulations," TSE Working Papers 22-1378, Toulouse School of Economics (TSE).

    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. Durrmeyer, Isis & Martinez, Nicolas, 2022. "The Welfare Consequences of Urban Traffic Regulations," TSE Working Papers 22-1378, Toulouse School of Economics (TSE).
    2. Small, Kenneth A., 2012. "Valuation of travel time," Economics of Transportation, Elsevier, vol. 1(1), pages 2-14.
    3. Kastl, Jakub & Buchholz, Nicholas & Doval, Laura & Matějka, Filip & Salz, Tobias, 2020. "The Value of Time: Evidence From Auctioned Cab Rides," CEPR Discussion Papers 14666, C.E.P.R. Discussion Papers.
    4. Buchholz, Nicholas & Doval, Laura & Kastl, Jakub & Matejka, Filip & Salz, Tobias, 2020. "The Value of Time: Evidence From Auctioned Cab Rides," CEPR Discussion Papers 14666, C.E.P.R. Discussion Papers.
    5. Jim Been & Susann Rohwedder & Michael Hurd, 2020. "Does Home Production Replace Consumption Spending? Evidence from Shocks in Housing Wealth in the Great Recession," The Review of Economics and Statistics, MIT Press, vol. 102(1), pages 113-128, March.
    6. Diane Coyle & Leonard Nakamura, 2022. "Time Use, Productivity, and Household-centric Measurement of Welfare in the Digital Economy," International Productivity Monitor, Centre for the Study of Living Standards, vol. 42, pages 165-186, Spring.
    7. Song, Chen & Wei, Chao, 2018. "Travel time use over five decades," Transportation Research Part A: Policy and Practice, Elsevier, vol. 116(C), pages 73-96.
    8. Wichman, Casey & Cunningham, Brandon, 2017. "Notching for Free: Do Cyclists Reveal the Value of Time?," RFF Working Paper Series 17-17, Resources for the Future.
    9. Enghin Atalay, 2022. "A Twenty-First Century of Solitude? Time Alone and Together in the United States," Working Papers 22-11, Federal Reserve Bank of Philadelphia.
    10. Han, Jeehoon & Meyer, Bruce D. & Sullivan, James X., 2020. "Inequality in the joint distribution of consumption and time use," Journal of Public Economics, Elsevier, vol. 191(C).
    11. Beaudoin, Justin & Lin Lawell, C.-Y. Cynthia, 2018. "The effects of public transit supply on the demand for automobile travel," Journal of Environmental Economics and Management, Elsevier, vol. 88(C), pages 447-467.
    12. Job Boerma & Loukas Karabarbounis, 2021. "Inferring Inequality With Home Production," Econometrica, Econometric Society, vol. 89(5), pages 2517-2556, September.
    13. Ken Yamada, 2010. "Intertemporal Substitution in the Time Allocation of Married Women," Working Papers 27-2010, Singapore Management University, School of Economics.
    14. Krekel, Christian & MacKerron, George, 2023. "Back to Edgeworth? Estimating the Value of Time Using Hedonic Experiences," IZA Discussion Papers 16308, Institute of Labor Economics (IZA).
    15. Djavad Salehi-Isfahani & Sara Taghvatalab, 2019. "Education and the allocation of time of married women in Iran," Review of Economics of the Household, Springer, vol. 17(3), pages 889-921, September.
    16. Juan Du & Takeshi Yagihashi, 2017. "Health capital investment and time spent on health-related activities," Review of Economics of the Household, Springer, vol. 15(4), pages 1215-1248, December.
    17. Eren Inci & Jos van Ommeren & Martijn Kobus, 2017. "The external cruising costs of parking," Journal of Economic Geography, Oxford University Press, vol. 17(6), pages 1301-1323.
    18. Richard Rogerson & Johanna Wallenius, 2009. "Retirement in a Life Cycle Model of Labor Supply with Home Production," Working Papers wp205, University of Michigan, Michigan Retirement Research Center.
    19. Otto Lenhart, 2018. "More than just the Adoption of Western Capitalism? Time Use Changes in East Germany Following Reunification," Journal of Labor Research, Springer, vol. 39(3), pages 306-328, September.
    20. Mark A. Aguiar & Erik Hurst & Loukas Karabarbounis, 2011. "Time Use During Recessions," NBER Working Papers 17259, National Bureau of Economic Research, Inc.

    More about this item

    JEL classification:

    • D0 - Microeconomics - - General
    • D1 - Microeconomics - - Household Behavior
    • R4 - Urban, Rural, Regional, Real Estate, and Transportation Economics - - Transportation Economics

    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:feb:natura:00720. 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: http://www.fieldexperiments.com .

    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: David Franks (email available below). General contact details of provider: http://www.fieldexperiments.com .

    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.