I’m an natural statistics skeptic. I disbelieve 78% of all statistics I read or hear.
In 1972-73, for example, just 42 percent of the bottom fifth of American households owned a car; in 2003, almost three-quarters of “poverty households” had one. By 2001, only 6 percent of “poverty households” lived in “crowded” homes (more than one person per room) – down from 26 percent in 1970. By 2003, the fraction of poverty households with central air-conditioning (45 percent) was much higher than the 1980 level for the non-poor (29 percent).
Emphasis mine. On first reading, this looks like a tremendous development. But I bolded the words for a good reason: we see three different terms used in the same paragraph: “bottom fifth”, “poverty households”, and “non-poor”. My legal training tells me, when I see three different terms, there are three different things meant. There are exceptions, of course, but statutes, provision, and even judicial opinions are drawn with careful attention to language.
The question here is: are the “bottom fifth”, “poverty households”, and “non-poor” the same group of people? My spider sense tells me “no”. If they’re roughly the same, there isn’t much problem. If they’re not, the statistics are essentially meaningless.
EDIT: Thanks to the somewhat anonymous Anarchist in the comments, I should clarify that I meant to ask whether the “non-poor” be identified with the top four-fifths, the non-poverty households, or something else entirely.