Table 3.

Determinants of willingness-to-accept HIV/STI prevention with conditional economic incentives among MSM^a in Mexico City

	(1) Accept monthly talks & STI tests for random $α1 per month	(2) Accept monthly talks & tests for bargaining incentive $α2 per month	(3) Accept to stay free of STIs for random incentive $α3 per quarter	(4) Accept to stay free of STI for bargaining incentive $α4 per quarter
Conditional incentive	0.0750	0.0519	0.0326	−0.0085
	[0.015]**	[0.015]**	[0.005]**	[0.003]**
Conditional incentive squared	−0.0066	−0.0069	−0.0009	−0.0000
	[0.001]**	[0.001]**	[0.000]**	[0.000]
Age (in years)	0.0248	0.0030	−0.0304	−0.0232
	[0.118]	[0.117]	[0.106]	[0.105]
Age squared	−0.0009	−0.0002	0.0005	0.0005
	[0.003]	[0.003]	[0.002]	[0.002]
Has HIV or STIb	−0.1470	0.0276	−0.0432	0.0155
	[0.053]**	[0.044]	[0.046]	[0.040]
Any condom use at last sexual act b,c	−0.0015	0.0314	0.0097	0.0561
	[0.041]	[0.040]	[0.037]	[0.038]
Male sex partners (last month)	0.0005	0.0137	0.0020	−0.0013
	[0.002]	[0.004]**	[0.002]	[0.002]
Last sex act with a partner whom respondent had just metb	0.0622	−0.0420	−0.0133	−0.0168
	[0.028]*	[0.028]	[0.026]	[0.025]
Has a stable partnerb	−0.0287	0.0023	0.0022	−0.0105
	[0.029]	[0.028]	[0.026]	[0.025]
Sex workerb	−0.0202	−0.1735	−0.0648	−0.0039
	[0.066]	[0.090]+	[0.064]	[0.057]
Studentb	−0.0043	−0.0300	−0.0058	0.0303
	[0.029]	[0.027]	[0.026]	[0.025]
Highest level of educationd	−0.0192	−0.0158	−0.0231	−0.0005
	[0.023]	[0.024]	[0.021]	[0.021]
Wealth indexe	−0.0020	−0.0158	−0.0171	−0.0142
	[0.019]	[0.017]	[0.017]	[0.016]
Observations	1,153	1,148	1,158	1,149
Pseudo R-squared	0.0483	0.147	0.0651	0.137
Probability	0.735	0.763	0.788	0.815

Notes: Table presents probit regression marginal effects. Robust standard errors in brackets:

^**p<0.01,

^*p<0.05,

⁺p<0.1

^aThe analytical samples consist of men who have sex with men (MSM), including male sex workers (MSW) with all the relevant covariate information. MSM defined as a man who has had sex with another man with anal penetration within the last year. The conditional incentive offers were random offers for α1 and α3. The incentive offers for α2, and α 4 were follow-up questions: a bargaining experimental game to increase participation and/or reduce program costs by increasing the incentive offer (for those who initially said “no”) or to lower the incentive offer (for those who initially said “yes”). Conditional incentive offer amounts are expressed in US dollars (USD) of 2008. Data collection took place during October 1-December 15, 2008 in Mexico City; the average exchange rate was 12.97 pesos per USD [29]

^bBinary variable.

^cAny condom use refers to use of condoms by respondent or male partner during last anal sex.

^dEducational levels were: Primary =1; Middle School=2; High School=3; College=4; Graduate=5.

^eThe wealth index was constructed using data on availability of: vehicle, own house, more than five rooms in the house, laptop and desktop computers, cable television, Internet access, and household help.