Andy Francis (Mr. Price of Sexual Desire himself) Responds to the Critics

Our latest Freakonomics column described a recent academic paper by Andy Francis. I asked him to respond to the comments that have been raised on our blog (see here). He was kind enough to oblige.

Here is what Andy has to say:

Thank you for all your comments. They were insightful, and I enjoyed reading them. Let me take a moment to comment on some of the themes that have emerged. Generally, I want to emphasize that the paper analyzes changes in sexuality *at the margin*. As the article and paper make clear, not everyone may respond to the AIDS epidemic, and those who respond may not respond in the same way. Nothing that I find is inconsistent with biology still playing a significant role. It is just that biology is not the whole story.

On stigma:

A few people have suggested that the findings may be attributable to stigma-related survey bias. That is, male respondents who have a relative with AIDS are especially stigmatized and are, hence, more likely to distort their survey responses to avoid appearing homosexual. While stigma is a real phenomenon, I don’t believe that stigma can rationalize the findings taken together. The following is an excerpt from page 28 of the paper: “First, male respondents who have a relative with AIDS freely admit to ever having done anything sexual with a man. Second, there is no evidence that men who have a relative with AIDS live in a social environment that is less tolerant of homosexuality. Having a relative with AIDS is uncorrelated with opinion of homosexuality (see Table 3). … Third, the NHSLS design ensures confidentiality and builds trust in a way which minimizes stigma, e.g. self-administered questionnaires cover sensitive topics. Fourth, it would be difficult for respondents to distort survey responses about children and marriage to a woman. Fifth, stigma does not rationalize why men who have a relative with AIDS are more likely to report ever having had anal sex with a woman. Sixth, evidence on the change in sexual behavior over time … is unrelated to having a relative with AIDS, but echoes the instrumental variables results. Lastly, stigma-related survey bias does not explain why women who have a relative with AIDS are more likely to report homosexual desire.”

On sample size:

Clearly, sample size is an issue. I try to do as much as I can with the data that exist. Whenever possible, I report small sample hypothesis tests (exact p-values). I believe that it is the pattern of results (not any one variable) that makes the case.
Take a look at all of the homosexual behavior, desire, and identity variables for men and women, in addition to the findings on anal sex with women,
ever having done anything sexual with someone of the same gender, the time series evidence on male homosexual behavior (before and after the invention of the AIDS “cocktail”), and homosexual behavior in the pre- and post-AIDS eras.

On politics:

The findings do not imply, in any sense, that homosexuality is morally wrong. This is a positive, not normative, paper. I do not want others to misconstrue my findings. All members of society deserve equality and respect. Virtually all liberal theories support this notion. I do not believe that it is necessary that sexual orientation be entirely biologically determined for homosexuals and bisexuals to merit and obtain equality and respect.

On the ambiguous illustration:

I too find the illustration quite puzzling. My current hypothesis is that the dashed lines represent a plot of economic variables over time. But maybe not.


SteveSailer

Mr. Francis should be commended for doing about as much as was possible with the sample size available to him. Anyone interested in dispassionate quantitative research on homosexuality should read it.

Unfortunately, for the contentious issue of the causes of _male_ homosexual behavior, his sample of a total of only 60 men with a relative with AIDS was simply too small for his findings to reach statistical significance even at the relative loose 5 percent level.

The percentage (4.4%) of men in the total sample who had engaged in homosexual acts in the last five years means that you'd expect only to find 2.64 such men out of his sample of 60. Instead of two or three, he found zero.

Is that meaningful? Maybe. Maybe not. Who knows?

Clearly, this study should be redone with an adequate sample size. Unfortunately, putting together a large enough and unbiased enough sample to do these kind of subtle analyses of male homosexuality has historically proven very difficult.

One concern is data-mining, or looking at a lot of relationships and then highlighting the ones that appear statistically unlikely to happen by chance. The 1992 database Mr. Francis used allows a large number of statistical tests to be run. If you looked at 100 different correlations, you'd expect to find and average of five that are statistically significant at the five percent level.

So, one relevant question is whether Mr. Francis started his research in order to test a pre-existing hypothesis that being exposed to people with AIDS would make a man less likely to engage in male homosexuality. I'd never heard the theory before, but perhaps it was going around in some circles.

I don't have a strong opinion on Mr. Francis's theory (Few doubt that female homosexual behavior is responsive to changing social pressures, but most researchers into homosexuality treat male and female homosexuality has highly distinct.) It sounds modestly plausible in theory, but I can't think of much historical evidence for it. The only bit of anecdotal evidence I can recall is that singer Lou Reed converted to heterosexuality (and stopped shooting heroin) right after AIDS was discovered. In contrast, San Francisco, for example, didn't see mass conversions to heterosexuality after 1982. Indeed, AIDS seemed to lead, if anything, to an increased public committment to homosexuality.

In summary, Mr. Francis has made a worthy beginning, but it desperately needs to be retested with an adequate sample size.

Dr. Levitt would have been better advised to publicize this study through this blog, where comments can expose the study's inevitable shortcomings rather than in the pages of the New York Times, where readers tend to be more credulous.

Read more...

Jerry

Very minor comment: I thought the dashed lines in the illustration represent the man's upraised arm covering his face. This suggests a dual desire/recoil of sex.

But more in line with the article, should the illustration depict a homosexual couple instead of a heterosexual one?

eeldrop

Not to obsess over the darn-blasted illustration, but the couple is in a stance associated with dancing, and, in that context, the dashed lines could be "motion lines"---like a dance instruction illustration, except, in this case, the motion line is associated with the mind...

J-blawg » Economics and epidemics

[...] Stephen J. Dubner and Steven D. Levitt (the Freakonomics guys) had a fascinating column in last weeks New York Times Magazine in which the described an economics paper that argued for the existence of an economic component to sexual preference (focusing on the AIDS epidemic). I’ll skip my own comments except to say that the piece is provocative. (Andy Francis, who wrote the original article, also responds to Dubner and Levitt on the Freakonomics Blog.) [...]

SteveSailer

By the way, Andy Francis was a research assistant to Dr. Levitt in 2003-2004.
http://home.uchicago.edu/~afrancis/Andrew_Francis_CV.pdf

And Mr. Francis describes the paper praised by Dr. Levitt in the New York Times as his "Job Market Paper."
http://home.uchicago.edu/~afrancis/research.html

While this apparent attempt by Dr. Levitt to use his column in the New York Times to help out an old student's job search certainly reflects well on his amiability, my vague impression is that the NYT typically prefers that its writers disclose this kind of conflict of interest to readers. Perhaps Dr. Levitt obtained a waiver of the disclosure policy in this case?

sophistry

I think Sailor should work for the CIA and help catch Al Qaeda terrorists. His superior acumen and polymath skills (econometrics expert, investigative journalist, propensity to write extremely long blogs every hour of every day) are clearly being wasted on quotidian trivialities such as the discovering the *gasp* true relationship between Francis and Levitt, the revelations of which are just beginning to reverberate across the academic ecosystem.

Large Type Blog » Blog Archive » Freakonomics authors make a big blunder

[...] The author of the paper upon which the study is based has come forward to defend his study in a separate posting. In the main, the defense is the study was truly anonymous; subjects should have felt safe to reveal their homosexual behaviors. [...]

Preston

Mr. Francis: I'm sorry I find your response to the issue of stigma rather unconvincing. Basically you say there is 'no evidence' to suggest that stigma is not the cause of decreased identification with homosexuality but perhaps that is just because the questions were not designed to detect this.

But, in any case, I found this to contradict your claim: Fifth, stigma does not rationalize why men who have a relative with AIDS are more likely to report ever having had anal sex with a woman.

I will admit to being on very uncertain ground here but would it not stand to reason that a homosexual who has chosen to avoid sex with men might choose instead to have sex with women in a similar fashion? The increased anal sex with women seems exactly to point to the fact that the men have not 'changed' their sexual orientation but are choosing to stay with women- either out of fear of disease or stigma.

Read more...

ritzjon

Speaking of stigma surrounding AIDS, did you know that Candace Pert, author of "Molecules of Emotion," discovered that the endogenous ligand to "peptide T" -- the one that can antagonize the receptor proteins generated by the AIDS virus -- is a peptide that's produced in the frontal lobe of the brain and is closely correlated with feelings of self love and self worth. This means that it the body produces a pethora of this peptide, it will float through the body and attach itself to the receptor proteins on infected cells and occupy that space, rendering it unavailable to attach to other cells; these are the very same receptor proteins that HIV tries to use to spread itself from one cell to another. Therefore, if someone infected with HIV can halt the spread of the disease through the body simply by feeling good about his or herself. Self Love, the highest emotion! Unfortunately, there is very high stigma associated with contracting the virus, and most patients find it very hard to feel upbeat given the highly negative social climate. If only society was more caring and nurturing, and maybe a little bit more understanding, AIDS patients would have a higher propensity of self love -- the true CURE for AIDS.

Read more...

vinaypande

the new york times article illustrates a novel kind, if not level, of intellectual dishonesty. it merely mentions the problem of small sample size yet goes on to assert conclusions that are completely unwarranted.
so i got my friend ( a professor in a school of public health at an ivy, and a prominent researcher in this field) to tell me in non-layman's terms whats wrong with this paper. he refuses to get involved in what he calls "low level non-intellectual discourse". so i pointed out to him the harm that these halfbaked theses can do if left unchecked for many years in the public realm. especially now that the internet is the leading source of information for lots of people. ( other examples of this would be supply side economics, objections to the global warming thesis and intelligent design; all pseudo science that when inflicted on the unwary readers of magazines like the new york times can, over time, acquire a false patina of truth.)
this is what my friend said and i quote..

"I looked at his blog and he doesn't address the sample size issue at all, he just mentions it. To reiterate the three issues I've already pointed out to you and (others)..... THE BOTTOM LINE IS: (1) There is not enough power in the data to support his conclusions. No respectable peer-reviewed journal would ever publish this work. Plus (2) it is cross-sectional data. You can't look at behavior change in cross-sectional data (PERIOD). And finally, (3) the measures of behavior are not valid (that is they are not necessarily measuring what you think they are measuring). You couldn't pass the most basic course in survey data analysis with this paper. END OF STORY."

Read more...

SteveSailer

Mr. Francis should be commended for doing about as much as was possible with the sample size available to him. Anyone interested in dispassionate quantitative research on homosexuality should read it.

Unfortunately, for the contentious issue of the causes of _male_ homosexual behavior, his sample of a total of only 60 men with a relative with AIDS was simply too small for his findings to reach statistical significance even at the relative loose 5 percent level.

The percentage (4.4%) of men in the total sample who had engaged in homosexual acts in the last five years means that you'd expect only to find 2.64 such men out of his sample of 60. Instead of two or three, he found zero.

Is that meaningful? Maybe. Maybe not. Who knows?

Clearly, this study should be redone with an adequate sample size. Unfortunately, putting together a large enough and unbiased enough sample to do these kind of subtle analyses of male homosexuality has historically proven very difficult.

One concern is data-mining, or looking at a lot of relationships and then highlighting the ones that appear statistically unlikely to happen by chance. The 1992 database Mr. Francis used allows a large number of statistical tests to be run. If you looked at 100 different correlations, you'd expect to find and average of five that are statistically significant at the five percent level.

So, one relevant question is whether Mr. Francis started his research in order to test a pre-existing hypothesis that being exposed to people with AIDS would make a man less likely to engage in male homosexuality. I'd never heard the theory before, but perhaps it was going around in some circles.

I don't have a strong opinion on Mr. Francis's theory (Few doubt that female homosexual behavior is responsive to changing social pressures, but most researchers into homosexuality treat male and female homosexuality has highly distinct.) It sounds modestly plausible in theory, but I can't think of much historical evidence for it. The only bit of anecdotal evidence I can recall is that singer Lou Reed converted to heterosexuality (and stopped shooting heroin) right after AIDS was discovered. In contrast, San Francisco, for example, didn't see mass conversions to heterosexuality after 1982. Indeed, AIDS seemed to lead, if anything, to an increased public committment to homosexuality.

In summary, Mr. Francis has made a worthy beginning, but it desperately needs to be retested with an adequate sample size.

Dr. Levitt would have been better advised to publicize this study through this blog, where comments can expose the study's inevitable shortcomings rather than in the pages of the New York Times, where readers tend to be more credulous.

Read more...

Jerry

Very minor comment: I thought the dashed lines in the illustration represent the man's upraised arm covering his face. This suggests a dual desire/recoil of sex.

But more in line with the article, should the illustration depict a homosexual couple instead of a heterosexual one?

eeldrop

Not to obsess over the darn-blasted illustration, but the couple is in a stance associated with dancing, and, in that context, the dashed lines could be "motion lines"---like a dance instruction illustration, except, in this case, the motion line is associated with the mind...

J-blawg » Economics and epidemics

[...] Stephen J. Dubner and Steven D. Levitt (the Freakonomics guys) had a fascinating column in last weeks New York Times Magazine in which the described an economics paper that argued for the existence of an economic component to sexual preference (focusing on the AIDS epidemic). I’ll skip my own comments except to say that the piece is provocative. (Andy Francis, who wrote the original article, also responds to Dubner and Levitt on the Freakonomics Blog.) [...]

SteveSailer

By the way, Andy Francis was a research assistant to Dr. Levitt in 2003-2004.
http://home.uchicago.edu/~afrancis/Andrew_Francis_CV.pdf

And Mr. Francis describes the paper praised by Dr. Levitt in the New York Times as his "Job Market Paper."
http://home.uchicago.edu/~afrancis/research.html

While this apparent attempt by Dr. Levitt to use his column in the New York Times to help out an old student's job search certainly reflects well on his amiability, my vague impression is that the NYT typically prefers that its writers disclose this kind of conflict of interest to readers. Perhaps Dr. Levitt obtained a waiver of the disclosure policy in this case?

sophistry

I think Sailor should work for the CIA and help catch Al Qaeda terrorists. His superior acumen and polymath skills (econometrics expert, investigative journalist, propensity to write extremely long blogs every hour of every day) are clearly being wasted on quotidian trivialities such as the discovering the *gasp* true relationship between Francis and Levitt, the revelations of which are just beginning to reverberate across the academic ecosystem.

Large Type Blog » Blog Archive » Freakonomics authors make a big blunder

[...] The author of the paper upon which the study is based has come forward to defend his study in a separate posting. In the main, the defense is the study was truly anonymous; subjects should have felt safe to reveal their homosexual behaviors. [...]

Preston

Mr. Francis: I'm sorry I find your response to the issue of stigma rather unconvincing. Basically you say there is 'no evidence' to suggest that stigma is not the cause of decreased identification with homosexuality but perhaps that is just because the questions were not designed to detect this.

But, in any case, I found this to contradict your claim: Fifth, stigma does not rationalize why men who have a relative with AIDS are more likely to report ever having had anal sex with a woman.

I will admit to being on very uncertain ground here but would it not stand to reason that a homosexual who has chosen to avoid sex with men might choose instead to have sex with women in a similar fashion? The increased anal sex with women seems exactly to point to the fact that the men have not 'changed' their sexual orientation but are choosing to stay with women- either out of fear of disease or stigma.

Read more...

ritzjon

Speaking of stigma surrounding AIDS, did you know that Candace Pert, author of "Molecules of Emotion," discovered that the endogenous ligand to "peptide T" -- the one that can antagonize the receptor proteins generated by the AIDS virus -- is a peptide that's produced in the frontal lobe of the brain and is closely correlated with feelings of self love and self worth. This means that it the body produces a pethora of this peptide, it will float through the body and attach itself to the receptor proteins on infected cells and occupy that space, rendering it unavailable to attach to other cells; these are the very same receptor proteins that HIV tries to use to spread itself from one cell to another. Therefore, if someone infected with HIV can halt the spread of the disease through the body simply by feeling good about his or herself. Self Love, the highest emotion! Unfortunately, there is very high stigma associated with contracting the virus, and most patients find it very hard to feel upbeat given the highly negative social climate. If only society was more caring and nurturing, and maybe a little bit more understanding, AIDS patients would have a higher propensity of self love -- the true CURE for AIDS.

Read more...

vinaypande

the new york times article illustrates a novel kind, if not level, of intellectual dishonesty. it merely mentions the problem of small sample size yet goes on to assert conclusions that are completely unwarranted.
so i got my friend ( a professor in a school of public health at an ivy, and a prominent researcher in this field) to tell me in non-layman's terms whats wrong with this paper. he refuses to get involved in what he calls "low level non-intellectual discourse". so i pointed out to him the harm that these halfbaked theses can do if left unchecked for many years in the public realm. especially now that the internet is the leading source of information for lots of people. ( other examples of this would be supply side economics, objections to the global warming thesis and intelligent design; all pseudo science that when inflicted on the unwary readers of magazines like the new york times can, over time, acquire a false patina of truth.)
this is what my friend said and i quote..

"I looked at his blog and he doesn't address the sample size issue at all, he just mentions it. To reiterate the three issues I've already pointed out to you and (others)..... THE BOTTOM LINE IS: (1) There is not enough power in the data to support his conclusions. No respectable peer-reviewed journal would ever publish this work. Plus (2) it is cross-sectional data. You can't look at behavior change in cross-sectional data (PERIOD). And finally, (3) the measures of behavior are not valid (that is they are not necessarily measuring what you think they are measuring). You couldn't pass the most basic course in survey data analysis with this paper. END OF STORY."

Read more...