Three effects I can see that haven’t been mentioned yet:
Prostitutes have a significantly lower life expectancy than non-prostitutes—a mortality rate 40 times as high. Overall mortality rate for, say, a 25 year old woman, is about 1 in 2000. For prostitutes, it’s thus about 1 in 50. Compound that for, say, ten years, and you get only 82% of prostitutes surviving past that point.
The lowest-class prostitutes would service the most men and have the highest mortality rate. If they have a 10% mortality rate per year (only five times worse than the average across all prostitutes) over a career of 10 years, then the whole cohort of women older than that point will have about 65% of them dead. After observing the horror of this, we note that death also renders one unable to respond to surveys.
Second effect: prostitutes especially but anyone highly promiscuous in general may have a hard time remembering just how many partners they’ve had, and may be poor at estimating it, even if they’re not trying to minimize it. Especially when they need to discount for repeat customers by a somewhat difficult to estimate margin… it’s a genuinely tough problem when you get up into the professional levels, at least without bookkeeping, which will frequently not be kept.
Third effect: prostitutes and ex-prostitutes, being especially disadvantaged, may be harder to reach.
Three effects I can see that haven’t been mentioned yet:
Prostitutes have a significantly lower life expectancy than non-prostitutes—a mortality rate 40 times as high. Overall mortality rate for, say, a 25 year old woman, is about 1 in 2000. For prostitutes, it’s thus about 1 in 50. Compound that for, say, ten years, and you get only 82% of prostitutes surviving past that point.
The lowest-class prostitutes would service the most men and have the highest mortality rate. If they have a 10% mortality rate per year (only five times worse than the average across all prostitutes) over a career of 10 years, then the whole cohort of women older than that point will have about 65% of them dead. After observing the horror of this, we note that death also renders one unable to respond to surveys.
Second effect: prostitutes especially but anyone highly promiscuous in general may have a hard time remembering just how many partners they’ve had, and may be poor at estimating it, even if they’re not trying to minimize it. Especially when they need to discount for repeat customers by a somewhat difficult to estimate margin… it’s a genuinely tough problem when you get up into the professional levels, at least without bookkeeping, which will frequently not be kept.
Third effect: prostitutes and ex-prostitutes, being especially disadvantaged, may be harder to reach.