Changes

==Undercount and Overcount==

==Undercount and Overcount==

Statisticians now estimate that the 1990 Census missed about 4.7 million people who should have been counted.  They estimate that the 2000 Census missed 6.4 million people, and double counted 3.1 million others, for a net undercount of 3.3 million. <ref> People who moved around were sometimes counted twice, as were some students and prisoners who were counted at home and at their institutions. See Freedman and Wachter (2004) pp. 6-8</ref>

Statisticians now estimate that the 1990 Census missed about 4.7 million people who should have been counted.  They estimate that the 2000 Census missed 6.4 million people, and double counted 3.1 million others, for a net undercount of 3.3 million. For example, millions of people refuse to answer the door and many will not fill out mailed forms. People who moved around are sometimes counted twice, as are some students and prisoners who can be counted at home and at their institutions. Children of divorced parents are often listed by both parents. Some households are so complicated or chaotic that the person filling out the forms is unclear who is living there today.<ref> See Freedman and Wachter (2004) pp. 6-8</ref>

==Further reading==

==Further reading==