In order to understand how evolution works in populations (of plants, animals, or humans), scientists need accurate population information. This includes not only the size of the population but also information about the animals or plants within the population. They need to know how many individuals in the population are young, middle-aged, or old; how many male, how many female; and genetic characteristics. This information lets scientists know not only whether the population (for example, of an endangered species) is in decline, but also the possible directions that evolution may take in the future.
Population information is also important as a basis for human societies. Governments need to know how many people live in each area, and their ages, so that they can plan revenues and expenditures. An aging population means lower revenues and higher expenditures, while a young population may mean just the opposite. This is exactly the kind of information that the Census, due this month, obtains.
Participation in the Census is required by the Constitution of the United States. Despite this, many people refuse to participate in the census, for reasons that are clearly incorrect and sometimes incoherent. Numerous conservative activists refuse to participate because (according to Republican representative Michele Bachmann) they think the government will use this information to locate conservatives and send them to internment camps. They think the Census is a Democratic plot to destroy them. Many of them also think that the government is specifically targeting illegal immigrants so as to increase expenditures in and congressional representatives from areas in which many illegal immigrants live.
But the opposite may be true. Hispanics, in particular, are being scared away from Census participation. The reason is that they fear that, by submitting their names and the names of family members and guests to the government, they are endangering arrest by immigration authorities. Even if the Hispanic householder that receives the form is a U.S. citizen, some of the residents of the household may not be, therefore the householder may not submit information to the Census even if he or she is a citizen and pays taxes. If you have received your census form, you may notice that the return address on the envelope is to the “Data Capture Center” in Phoenix. Now what is a Hispanic to think when asked to submit personal information to a “capture center”?
The conservatives, with typical fearmongering, claim that the Census is a trick to over-represent Democratic areas by counting illegal immigrants. However, the opposite is just as likely to be true. This is also part of the general conservative dislike of data. They want people to believe their broad and incorrect generalization, rather than to base opinions upon scientifically-collected data.