This includes the income of the householder and all other individuals 15 years old and over in the household, whether they are related to the householder or not. Because many households consist of only one person, average household income is usually less than average family income. Although the household income statistics cover the past 12 months, the characteristics of individuals and the composition of households refer to the time of interview. Thus, the income of the household does not include amounts received by individuals who were members of the household during all or part of the past 12 months if these individuals no longer resided in the household at the time of interview. Similarly, income amounts reported by individuals who did not reside in the household during the past 12 months but who were members of the household at the time of interview are included. However, the composition of most households was the same during the past 12 months as at the time of interview.

Income components were reported for the 12 months preceding the interview month. Monthly Consumer Price Indices (CPI) factors were used to inflation-adjust these components to a reference calendar year (January through December). For example, a household interviewed in March 2007 reports their income for March 2007 through February 2007. Their income is adjusted to the 2007 reference calendar year by multiplying their reported income by 2007 average annual CPI (January-December 2007) and then dividing by the average CPI for March 2006-February2007.
In order to inflate income amounts from previous years, the dollar values on individual records are inflated to the latest years dollar values by multiplying by a factor equal to the average annual CPI-U-RS factor for the current year, divided by the average annual CPI-U-RS factor for the earlier/earliest year.

The data on relationship to householder were derived from answers to Question 3, which was asked of all people in housing units. One person in each household is designated as the householder. In most cases, this is the person, or one of the people, in whose name the home is owned, being bought, or rented and who is listed on line one of the survey questionnaire. If there is no such person in the household, any adult household member 15 years old and over could be designated as the householder. Households are classified by type according to the sex of the householder and the presence of relatives. Two types of householders are distinguished: a family householder and a non-family householder. A family householder is a householder living with one or more individuals related to him or her by birth, marriage, or adoption. The householder and all people in the household related to him or her are family members. A non-family householder is a householder living alone or with non-relatives only.

People may have chosen to provide two or more races either by checking two or more race response check boxes, by providing multiple responses, or by some combination of check boxes and write-in responses. The race response categories shown on the questionnaire are collapsed into the five minimum races identified by the OMB, and the Census Bureau's "Some other race" category. For data product purposes, "Two or More Races" refers to combinations of two or more of the following race categories:
1. White
2. Black or African American
3. American Indian and Alaska Native
4. Asian
5. Native Hawaiian and Other Pacific Islander
6. Some other race

There are 57 possible combinations (see below) involving the race categories shown above. Thus, according to this approach, a response of "White" and "Asia"n was tallied as two or more races, while a response of Japanese and Chinese was not because "Japanese" and "Chinese" are both Asian responses. Tabulations of responses involving reporting of two or more races within the American Indian and Alaska Native, Asian, or Native Hawaiian and Other Pacific Islander categories are available in other data products.

1. White; Black or African American


2. White; American Indian and Alaska Native


3. White; Asian


4. White; Native Hawaiian and Other Pacific Islander


5. White; Some other race


6. Black or African American; American Indian and Alaska Native


7. Black or African American; Asian


8. Black or African American; Native Hawaiian and Other Pacific Islander


9. Black or African American; Some other race


10. American Indian and Alaska Native; Asian


11. American Indian and Alaska Native; Native Hawaiian and Other Pacific Islander


12. American Indian and Alaska Native; Some other race


13. Asian; Native Hawaiian and Other Pacific Islander


14. Asian; Some other race


15. Native Hawaiian and Other Pacific Islander; Some other race


16. White; Black or African American; American Indian and Alaska Native


17. White; Black or African American; Asian


18. White; Black or African American; Native Hawaiian and Other Pacific Islander


19. White; Black or African American; Some other race


20. White; American Indian and Alaska Native; Asian


21. White; American Indian and Alaska Native; Native Hawaiian and Other Pacific Islander


22. White; American Indian and Alaska Native; Some other race


23. White; Asian; Native Hawaiian and Other Pacific Islander


24. White; Asian; Some other race


25. White; Native Hawaiian and Other Pacific Islander; Some other race


26. Black or African American; American Indian and Alaska Native; Asian


27. Black or African American; American Indian and Alaska Native; Native Hawaiian and Other Pacific Islander


28. Black or African American; American Indian and Alaska Native; Some other race


29. Black or African American; Asian; Native Hawaiian and Other Pacific Islander


30. Black or African American; Asian; Some other race


31. Black or African American; Native Hawaiian and Other Pacific Islander; Some other race


32. American Indian and Alaska Native; Asian; Native Hawaiian and Other Pacific Islander


33. American Indian and Alaska Native; Asian; Some other race


34. American Indian and Alaska Native; Native Hawaiian and Other Pacific Islander; Some other race


35. Asian; Native Hawaiian and Other Pacific Islander; Some other race


36. White; Black or African American; American Indian and Alaska Native; Asian


37. White; Black or African American; American Indian and Alaska Native; Native Hawaiian and Other Pacific Islander


38. White; Black or African American; American Indian and Alaska Native; Some other race


39. White; Black or African American; Asian; Native Hawaiian and Other Pacific Islander


40. White; Black or African American; Asian; Some other race


41. White; Black or African American; Native Hawaiian and Other Pacific Islander; Some other race


42. White; American Indian and Alaska Native; Asian; Native Hawaiian and Other Pacific Islander


43. White; American Indian and Alaska Native; Asian; Some other race


44. White; American Indian and Alaska Native; Native Hawaiian and Other Pacific Islander; Some other race


45. White; Asian; Native Hawaiian and Other Pacific Islander; Some other race


46. Black or African American; American Indian and Alaska Native; Asian; Native Hawaiian and Other Pacific Islander


47. Black or African American; American Indian and Alaska Native; Asian; Some other race


48. Black or African American; American Indian and Alaska Native; Native Hawaiian and Other Pacific Islander; Some other race


49. Black or African American; Asian; Native Hawaiian and Other Pacific Islander; Some other race


50. American Indian and Alaska Native; Asian; Native Hawaiian and Other Pacific Islander; Some other race


51. White; Black or African American; American Indian and Alaska Native; Asian; Native Hawaiian and Other Pacific Islander


52. White; Black or African American; American Indian and Alaska Native; Asian; Some other race


53. White; Black or African American; American Indian and Alaska Native; Native Hawaiian and Other Pacific Islander; Some other race


54. White; Black or African American; Asian; Native Hawaiian and Other Pacific Islander; Some other race


55. White; American Indian and Alaska Native; Asian; Native Hawaiian and Other Pacific Islander; Some other race


56. Black or African American; American Indian and Alaska Native; Asian; Native Hawaiian and Other Pacific Islander; Some other race


57. White; Black or African American; American Indian and Alaska Native; Asian; Native Hawaiian and Other Pacific Islander; Some other race

Given the many possible ways of displaying data on two or more races, data products will provide varying levels of detail. The most common presentation shows a single line indicating "Two or more races." Some data products provide totals of all 57 possible race combinations, as well as subtotals of people reporting a specific number of races, such as people reporting two races, people reporting three races, and so on. In other presentations on race, data are shown for the total number of people who reported one of the six categories alone or in combination with one or more other race categories. For example, the category, "Asian alone or in combination with one or more other races" includes people who reported Asian alone and people who reported Asian in combination with White, Black or African American, Native Hawaiian and Other Pacific Islander, and/or Some other race. This number, therefore, represents the maximum number of people who reported as Asian in the question on race. When this data presentation is used, the individual race categories will add to more than the total population because people may be included in more than one category.