Notes from the Field: Xlab Research in Mexico
by Omar Galárraga

12 December 2008

To: Institute of Business and Economic Research
University of California, Berkeley CA 94720-1922

This is a note to thank you for letting us use the hand-held computers from the X-Lab at UC Berkeley. They worked very well: during October-November 2008, we conducted over 1,700 interviews among men who have sex with men (MSM) and male sex workers (MSW) in Mexico City.

We collected information on willingness to participate and accept economic incentives conditional upon being free of sexually transmitted infections (STIs). The target population was young MSM and MSW (ages 18 to 25). The work was completed in collaboration with members of the local community who know the formal and informal meeting places and have worked with the population for many years. The overall objective of the project was to inform future HIV/AIDS prevention projects.

We programmed about 80 questions into the hand-held computers. The interview lasted 30 minutes on average. The participants could respond to the questions directly into the computers or have the questions read to them by the interviewer. The preferred approach was to have the interviewees self-administer the interview because we included questions about their sexual experiences. Respondents tend to be more truthful when the interview is completely anonymous and confidential.

We used standard contingency evaluation methods, including random-starting-point and iterative bidding to estimate willingness to accept conditional cash transfers for HIV and STI prevention. Each subject was asked if he would enroll in the prevention program given a set level of incentives. To avoid a starting point bias in the willingness to accept questions, the computers would pick a random number (from a given range) to start the bidding process: “Would you be willing to participate in the prevention program for an incentive of $X pesos per month?” Follow-up questions would ensue, raising the bid if the respondent did not accept the first offer, or lowering the bid if the respondent did accept the first offer.

The hand-held computers were also very helpful because they were discrete. Some of the interviews were conducted in bars, on busy streets, plazas, and metro stations. Thus, for security and anonymity, having very small devices was very useful.

Sincerely,
Omar Galárraga, Ph.D.

Dr. Omar Galárraga is a postdoctoral researcher at IBER, funded under a five-year grant from NIH’s Fogarty International Center for work on “Conditional Cash Transfers to Prevent Sexually Transmitted Infections in Mexico.” The base for his field research in Mexico is the National Institute of Public Health in Cuernavaca.