On the Top Ten list of things I wish I’d thought of doing with my household survey data:
Their paper takes advantage of a remarkably rich data set from Oportunidades, a Mexican welfare program. It records the household goods that people say they have when they are applying for the program and then it also records the household goods that are actually found to be in that household once the recipient’s application has been accepted. Martinelli and Parker worked with data from more than 100,000 applicants, representing 10 percent of the applicants interviewed that year (2002).
It turned out that a lot of people underreported certain items that they thought might exclude them from getting benefits. Below is a list of underreported items followed by the percentage of recipients who owned a certain good but who said they didn’t:
Car (83.10 percent)
Truck (81.71)
Video recorder (79.73)
Satellite TV (73.91)
Gas boiler (73.12)
Phone (73.12)
Washing machine (53.46)That’s not very surprising: you might expect people to lie to gain the advantage of a welfare benefit. But here’s the surprise. Below is a list of household items that were overreported — i.e., which applicants said they had but in fact did not (again, followed by percentages):
Toilet (39.07 percent)
Tap water (31.76)
Gas stove (28.56)
Concrete floor (25.41)
Refrigerator (12.05)So 4 out of 10 applicants without a toilet said they had one. Why?
Martinelli and Parker chalk it up to embarrassment, plain and simple.
Read the rest on the Freakonomics blog.
The paper is “Deception and Misreporting in a Social Program,†by Cesar Martinelli and Susan Parker.
There’s an answer simpler, even, than embarrassment. When you ask someone “Does your house have toilet facilities?” people might hear “Do the people in your house have access to a place to relieve themselves?”
That is, unless the interviewers took time to carefully define what they mean by “modern, urban-style porcelain flush toilet”, people could easily freely interpret that, and they could also misinterpret “have” as “have access to”.
The same thing would be very unlikely to happen with satellite TV — it’s hard to mistake anything you have that isn’t satellite TV for satellite TV. And there’s rarely such thing as “community satellite TV”, to which everyone has access, whereas “community toilet” to which everyone has access is common.
I agree with Michael – I wonder how precise the questions were.