Abstract
The objective of this study was to measure willingness-to-accept (WTA) reductions in risks for HIV and other sexually transmitted infections (STI) using conditional economic incentives (CEI) among men who have sex with men (MSM), including male sex workers (MSW) in Mexico City. A survey experiment was conducted with 1,745 MSM and MSW (18–25 years of age) who received incentive offers to decide first whether to accept monthly prevention talks and STI testing; and then a second set of offers to accept to stay free of STIs (verified by quarterly biological testing). The survey used random-starting-point and iterative offers. WTA was estimated with a maximum likelihood double-bounded dichotomous choice model. The average acceptance probabilities were: 73.9 % for the monthly model, and 80.4 % for the quarterly model. The incentive-elasticity of participation in the monthly model was 0.222, and 0.515 in the quarterly model. For a combination program with monthly prevention talks, and staying free of curable STI, the implied WTA was USD$ 288 per person per year, but it was lower for MSW: USD$ 156 per person per year. Thus, some of the populations at highest risk of HIV infection (MSM and MSW) seem well disposed to participate in a CEI program for HIV and STI prevention in Mexico. The average WTA estimate is within the range of feasible allocations for prevention in the local context. Given the potential impact, Mexico, a leader in conditional cash transfers for human development and poverty reduction, could extend that successful model to targeted HIV/STI prevention.
References
Coates, T.J., Richter, L., Caceres, C.: Behavioural strategies to reduce HIV transmission: how to make them work better. Lancet 372(9639), 669–684 (2008)
Padian, N.S., Buve, A., Balkus, J., Serwadda, D., Cates Jr, W.: Biomedical interventions to prevent HIV infection: evidence, challenges, and way forward. Lancet 372(9638), 585–599 (2008)
Gupta, G.R., Parkhurst, J.O., Ogden, J.A., Aggleton, P., Mahal, A.: Structural approaches to HIV prevention. Lancet 372(9640), 764–775 (2008)
Baird, S.J., Garfein, R.S., McIntosh, C.T., Ozler, B.: Effect of a cash transfer programme for schooling on prevalence of HIV and herpes simplex type 2 in Malawi: a cluster randomised trial. Lancet 379(9823), 1320–1329 (2012). doi:10.1016/S0140-6736(11)61709-1
de Walque, D., Dow, W.H., Nathan, R., Abdul, R., Abilahi, F., Gong, E., Isdahl, Z., Jamison, J., Jullu, B., Krishnan, S., Majura, A., Miguel, E., Moncada, J., Mtenga, S., Mwanyangala, M.A., Packel, L., Schachter, J., Shirima, K., Medlin, C.A.: Incentivising safe sex: a randomised trial of conditional cash transfers for HIV and sexually transmitted infection prevention in rural Tanzania. BMJ Open 2, e000747 (2012). doi:10.1136/bmjopen-2011-000747
Baird, S.J., McIntosh, C., Ozler, B.: Cash or condition? Evidence from a cash transfer experiment. Q. J. Econ. 126, 1709–1753 (2011)
Lagarde, M., Haines, A., Palmer, N.: Conditional cash transfers for improving uptake of health interventions in low- and middle-income countries: a systematic review. JAMA 298(16), 1900–1910 (2007)
Adato, M., Hoddinott, J.: Conditional Cash Transfers in Latin America. Johns Hopkins University Press, Baltimore (2010)
Gertler, P.: Do conditional cash transfers improve child health? Evidence from PROGRESA’s control randomized experiment. Am. Econ. Rev. 94(2), 336–341 (2004)
Barber, S.L., Gertler, P.J.: Empowering women to obtain high quality care: evidence from an evaluation of Mexico’s conditional cash transfer programme. Health Policy Plan 24(1), 18–25 (2009)
Barham, T., Maluccio, J.A.: Eradicating diseases: the effect of conditional cash transfers on vaccination coverage in rural Nicaragua. J. Health Econ. 28(3), 611–621 (2009)
Barber, S.L., Gertler, P.J.: The impact of Mexico’s conditional cash transfer programme, Oportunidades, on birthweight. Trop. Med. Int. Health 13(11), 1405–1414 (2008)
Fernald, L.C., Gertler, P.J., Neufeld, L.M.: Role of cash in conditional cash transfer programmes for child health, growth, and development: an analysis of Mexico’s Oportunidades. Lancet 371(9615), 828–837 (2008)
Fernald, L.C., Gunnar, M.R.: Poverty-alleviation program participation and salivary cortisol in very low-income children. Soc. Sci. Med. 68(12), 2180–2189 (2009)
Fernald, L.C., Gertler, P.J., Neufeld, L.M.: 10-Year effect of Oportunidades, Mexico’s conditional cash transfer programme, on child growth, cognition, language, and behaviour: a longitudinal follow-up study. Lancet 374(9706), 1997–2005 (2009)
Leroy, J.L., Garcia-Guerra, A., Garcia, R., Dominguez, C., Rivera, J., Neufeld, L.M.: The Oportunidades program increases the linear growth of children enrolled at young ages in urban Mexico. J. Nutr. 138(4), 793–798 (2008)
Grossman, M.: Concept of health capital and demand for health. J. Polit. Econ. 80(2), 223–225 (1972)
Michael, R.T.: Sexual capital: an extension of Grossman’s concept of health capital. J. Health Econ. 23(4), 643–652 (2004)
Laibson, D.: Golden eggs and hyperbolic discounting. Q. J. Econ. 112(2), 443–477 (1997)
Rao, V., et al.: Sex workers and the cost of safe sex: the compensating differential for condom use among Calcutta prostitutes. J. Dev. Econ. 71(2), 585–603 (2003)
Gertler, P., Shah, M., Bertozzi, S.M.: Risky business: the market for unprotected commercial sex. J. Polit. Econ. 113(3), 518–550 (2005)
Magnani, R., Sabin, K., Saidel, T., Heckathorn, D.: Review of sampling hard-to-reach and hidden populations for HIV surveillance. AIDS 19(Suppl 2), S67–S72 (2005)
MacKellar, D., Valleroy, L., Karon, J., Lemp, G., Janssen, R.: The young men’s survey: methods for estimating HIV seroprevalence and risk factors among young men who have sex with men. Public Health Rep. 111(Suppl 1), 138–144 (1996)
MacKellar, D.A., Gallagher, K.M., Finlayson, T., Sanchez, T., Lansky, A., Sullivan, P.S.: Surveillance of HIV risk and prevention behaviors of men who have sex with men—a national application of venue-based, time-space sampling. Public Health Rep. 122(Suppl 1), 39–47 (2007)
Gutierrez, J.P.: Profile of gay men in Mexico City: results of a survey of meeting sites. Trop. Med. Int. Health 17(3):353–360 (2011). doi:10.1111/j.1365-3156.2011.02934.x
McFadden, D.L., Bemmaor, A.C., Caro, F.G., Dominitz, J., Jun, B.H., Lewbel, A., Matzkin, R.L., Molinari, F., Schwarz, N., Willis, R.J., Winter, J.K.: Statistical analysis of choice experiments and surveys. Mark. Lett. 16(3–4), 183–196 (2005). doi:10.1007/s11002-005-5884-2
DeShazo, J.R.: Designing transactions without framing effects in iterative question formats. J. Environ. Econ. Manag. 43(3), 360–385 (2002). doi:10.1006/jeem.2000.1185
Infante, C., Sosa-Rubi, S.G., Cuadra, S.M.: Sex work in Mexico: vulnerability of male, travesti, transgender and transsexual sex workers. Cult. Health Sex, 11(2), 125–137 (2009)
IMF: international exchange rates. http://www.imf.org/external/data.htm (2008). Accessed 14 September 2010
Hanemann, M., Loomis, J., Kanninen, B.: Statistical efficiency of double-bounded dichotomous choice contingent valuation. Am. J. Agric. Econ. 73(4), 1255–1263 (1991)
Fan, J.Q.: Design-adaptive nonparametric regression. J. Am. Stat. Assoc. 87(420), 998–1004 (1992)
Thornton, R.L.: The demand for, and impact of, learning HIV status. Am. Econ. Rev. 98(5), 1829–1863 (2008)
Baird, S., Chirwa, E., McIntosh, C., Ozler, B.: The short-term impacts of a schooling conditional cash transfer program on the sexual behavior of young women. Health Econ. 19(Suppl), 55–68 (2010). doi:10.1002/hec.1569
Bautista-Arredondo, S., Colchero, M.A., Sosa-Rubí, S.G., Romero, M., Conde, C.: Diagnóstico situacional, mapeo de sitios de encuentro y evaluación de impacto de las estrategias de prevención en México. Informe sobre la encuesta en sitios de encuentro de HSH. [Diagnostic assessment, mapping of meeting places, and impact evaluation of HIV prevention strategies in Mexico: report on the survey for meeting places for men who have sex with men]. In. National Institute of Public Health (INSP), Cuernavaca, Mexico, (2012)
Tversky, A., Kahneman, D.: Belief in law of small numbers. Psychol. Bull. 76(2), 105–110 (1971)
Sheeran, P., Abraham, C., Orbell, S.: Psychosocial correlates of heterosexual condom use: a meta-analysis. Psychol. Bull. 125(1), 90–132 (1999). doi:10.1037//0033-2909.125.1.90
Michielsen, K., Chersich, M.F., Luchters, S., De Koker, P., Van Rossem, R., Temmerman, M.: Effectiveness of HIV prevention for youth in sub-Saharan Africa: systematic review and meta-analysis of randomized and nonrandomized trials. AIDS 24(8), 1193–1202 (2010)
Johnson, W.D., Diaz, R.M., Flanders, W.D., Goodman, M., Hill, A.N., Holtgrave, D., Malow, R., McClellan, W.M.: Behavioral interventions to reduce risk for sexual transmission of HIV among men who have sex with men. Cochrane Database Syst Rev (3), CD001230 (2008). doi:10.1002/14651858.CD001230.pub2
Sangani, P., Rutherford, G., Wilkinson, D.: Population-based interventions for reducing sexually transmitted infections, including HIV infection. Cochrane Database Syst Rev (2), CD001220 (2004). doi:10.1002/14651858.CD001220.pub2
Wariki, W.M., Ota, E., Mori, R., Koyanagi, A., Hori, N., Shibuya, K.: Behavioral interventions to reduce the transmission of HIV infection among sex workers and their clients in low- and middle-income countries. Cochrane Database Syst Rev 2, CD005272 (2012). doi:10.1002/14651858.CD005272.pub3
Ota, E., Wariki, W.M., Mori, R., Hori, N., Shibuya, K.: Behavioral interventions to reduce the transmission of HIV infection among sex workers and their clients in high-income countries. Cochrane Database Syst Rev (12), CD006045 (2011). doi:10.1002/14651858.CD006045.pub3
Galárraga, O., Colchero, A., Wamai, R., Bertozzi, S.: HIV prevention cost effectiveness: a review of the recent literature. BMC Public Health 9(Suppl 1), S5 (2009)
Todd, P.E., Wolpin, K.I.: Assessing the impact of a school subsidy program in Mexico: using a social experiment to validate a dynamic behavioral model of child schooling and fertility. Am. Econ. Rev. 96(5), 1384–1417 (2006)
Bourguignon, F., Ferreira, F.H.G., Leite, P.G.: Conditional cash transfers, schooling, and child labor: micro-simulating Brazil’s Bolsa Escola program. World Bank Econ. Rev. 17(2), 229–254 (2003). doi:10.1093/Wber/Lhg018
Filmer, D., Schady, N.: Does more cash in conditional cash transfer programs always lead to larger impacts on school attendance? J. Dev. Econ. 96(1), 150–157 (2011). http://www.elsevier.com/wps/find/journaldescription.cws_home/505546/description#description
McFadden, D.: Contingent valuation and social choice. Am. J. Agric. Econ. 76(4), 689–708 (1994). http://ajae.oxfordjournals.org/content/by/year
Blumenschein, K., Blomquist, G.C., Johannesson, M., Horn, N., Freeman, P.: Eliciting willingness to pay without bias: evidence from a field experiment. Econ. J. 118(525), 114–137 (2008)
Johannesson, M.: A note on the relationship between ex ante and expected willingness to pay for health care. Soc. Sci. Med. 42(3), 305–311 (1996)
Kahneman, D.: A perspective on judgment and choice—mapping bounded rationality. Am. Psychol. 58(9), 697–720 (2003). doi:10.1037/0003-066x.58.9.697
López-Feldman, A.: DOUBLEB: Stata module to compute contingent valuation using double-bounded dichotomous choice. In: IDEAS, R. (ed.) Stata Command to Use Maximum Likelihood (under the Assumption of Normality) to Estimate the Double-Bounded Dichotomous Choice Model for Contingent Valuation Proposed by Hanemann, Loomis and Kanninen (1991). CIDE, División de Economía, Mexico City, Mexico, (2011)
Acknowledgments
Useful comments were provided by Jim Berry, Will Dow, Jason Fletcher, Ralph Gonzales, Sandi McCoy, Kevin Volpp, two anonymous referees, and participants at seminars (Mexican School of Public Health, University of California-San Francisco, University of Pennsylvania, Yale University, and University of North Carolina-Chapel Hill) and conferences (7th World Congress of the International Health Economics Association-iHEA—3rd biennial American Society of Health Economists-ASHE—and the XVIII AIDS International Conference). We particularly thank the survey respondents in Mexico City; as well as Luis Pozo-Urquizo, Paola Olivieri, Edgar Ávila and Moisés Calderón of La Manta de México for their involvement in data collection and field work. Research assistance was provided by Fernando Alarid-Escudero. The questionnaire was programmed into the hand-held devices by Edgar Díaz and his team at CEO/Mexico. Alejandro López-Feldman provided additional background material to adapt the Stata ado file “doubleb.” The project benefitted from input of faculty and staff at the Institute of Business and Economic Research (IBER) and the Experimental Social Science Laboratory (X-Lab) at UC Berkeley. We gratefully acknowledge funding from the US National Institutes of Health/Fogarty International Center (Grant No. K01-TW008016-04 PI: Galárraga); and Mexican National Center for HIV/AIDS Control and Prevention (CENSIDA, Prevention Grant 2008).
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Appendix Exhibit A: Willingness-to-accept questions (survey instrument)
Appendix Exhibit A: Willingness-to-accept questions (survey instrument)
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Galárraga, O., Sosa-Rubí, S.G., Infante, C. et al. Willingness-to-accept reductions in HIV risks: conditional economic incentives in Mexico. Eur J Health Econ 15, 41–55 (2014). https://doi.org/10.1007/s10198-012-0447-y
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DOI: https://doi.org/10.1007/s10198-012-0447-y
Keywords
- Willingness-to-accept
- Conditional economic incentive
- HIV/AIDS and STI prevention
- Contingency management/conditional cash transfer
- Mexico