Social desirability bias is the idea that people responding to surveys or other forms of data collection will say the socially correct answer rather than what they really think. A sociologist argues that this is the case for immigration polls:

A Gallup survey taken last year found 45 percent believe immigration should be decreased, compared to 17 percent saying it should be increased and 34 percent saying it should be kept at present levels. But should such figures be taken at face value? University of California, Berkeley, sociologist Alexander Janus argues not. Using a polling technique designed to uncover hidden bias, he concluded about 61 percent of Americans support a cutoff of immigration. Janus, who published his findings in the journal Social Science Quarterly, argues that “social desirability pressures” lead many on the left to lie about their true feelings on immigration — even when asked in an anonymous poll. In an interview, he discussed the survey he conducted in late 2005 and early 2006:

THE SURVEY: “The survey participants were first split into two similar groups. Individuals in one of the groups were presented with three concepts — ‘The federal government increasing assistance to the poor,’ ‘Professional athletes making millions of dollars per year,’ and ‘Large corporations polluting the environment’ — and asked how many of the three they opposed. Individuals in the second group were given the same three items as individuals in the first group, plus an immigration item: ‘Cutting off immigration to the United States.’ They were asked how many of the four they opposed. The difference in the average number of items named between the two groups can be attributed to opposition to the immigration item. The list experiment is superior to traditional questioning techniques in the sense that survey participants are never required to reveal to the interviewer their true attitudes or feelings.”…

I estimated that about 6 in 10 college graduates and more than 6 in 10 liberals hide their opposition to immigration when asked directly, using traditional survey measures.”

This sounds like an interesting technique because as he mentions, the respondents never have to say exactly which ideas they are opposed to.

In the long run for immigration policy, does it matter that much for liberals if people are secretly against immigration if they are willing to support it publicly? Of course, it could influence individual or small group interactions and how willing people are to participate in rallies and public events. But if people are still willing to vote in a socially desirable way, is this good enough?

I wonder if there are other numbers out there that are influenced by social desirability bias…