Sources and Notes for Neighborhood Profiles

This page provides basic information for interpreting the indicators in the NeighborhoodInfo DC neighborhood profiles and describes the sources of data used to create them. If you have additional questions, please contact us at info@neighborhoodinfodc.org

Select the heading for sources and notes on topics of interest.

General Notes and Sources
Geography
Columns
Population tab
Total
Race/Ethnicity
Foreign-Born
Families
Low weight births
Births to teen mothers
Well-Being tab
Poverty
Employment
Education
Isolation
Family Income
Food Stamps
TANF
Violent Crimes
Property Crimes
Housing tab
Housing Units
Mobility
Rental Vacancy
Homeownership
Sales of Single-Family Homes
Price of Single-Family Homes
Mortgage Lending
Mortgage Borrower Income
Subprime Lending
Foreclosures tab
SF Homes/Condos Receiving Foreclosure Notice
Foreclosure Notice Rate
SF Homes/Condos Receiving Trustee Deed Sale Notice
Trustee Deed Sale Rate
Schools tab
Number of Schools
Audited Enrollment

General Notes

Data used to create the neighborhood profiles comes from a variety of sources, including the decennial U.S. Census, the American Community Survey, and local administrative data sources. NeighborhoodInfo DC standardizes these data to allow comparisons over time of consistent indicators across different geographic areas.

Some of the source data are provided for geographic areas, such as Census tracts and block groups, which do not line up perfectly with other D.C. geographies (e.g. wards, zip codes, etc). NeighborhoodInfo DC has mapped these data to each set of geographical boundaries using population weights to split tracts or block groups, when necessary. As a consequence, some of the data in the neighborhood profiles by ward, Advisory Neighborhood Commission (ANC), neighborhood cluster, Police Service Area (PSA), and zip code are close approximations, rather than precise counts.

NEW: Data have been updated to include the 2010 Census Geographies and to include the margins of error.

The ACS is a national survey of households and housing units, administered by the U.S. Census Bureau on an ongoing basis. The ACS replaces the decennial Census long form, which was administered only once every ten years, collecting much of the same information on demographics, poverty, employment, housing, and other detailed characteristics. While the ACS offers the advantage of more frequent data collection, it has a smaller sample size than the long form. To obtain reliable estimates for small areas, multiple years of ACS data must be combined to produce a single indicator. For subareas in DC, we must use the ACS 5-year estimates, which combine data for 60 consecutive months of surveys.

Data based on the American Community Survey (ACS) 5-year estimates are included in the profiles. The ACS data in the neighborhood profiles are updated based on the most recent 5-year ACS data. The actual value can be thought of as an average over this 5-year period.

With each ACS estimate, the Census Bureau reports a margin of error (MOE), or measure of the variability of the estimate due to sampling error. The MOE enables data users to measure the range of uncertainty around each estimate. The larger the MOE, the lower the accuracy of the estimate-and the less confidence one should have that the estimate is close to the true value.

More information on the ACS can be found on the Census Bureau's web site.

Geography

ANCs: Advisory Neighborhood Commissions (ANCs) are political jurisdictions designed to represent the views of neighborhood residents to the District government. There are 37 ANCs in the city, each of which has an advisory board made up of neighborhood residents.

Census tracts: Census tracts are locally-defined statistical areas used by the U.S. Census Bureau for collecting and tabulating census data. Most tracts have between 2,500 and 8,000 persons and, when first defined, are intended to be homogeneous with respect to population characteristics, economic status, and living conditions. Tract definitions change every 10 years with the decennial census. For the 2010 census, there were 179 Census Tracts defined in the District of Columbia. Census Tracts are small, relatively permanent statistical subdivisions of a county. Census Tract boundaries are delineated with the intention of being maintained over a long time so that statistical comparisons can be made from census to census. Note: We provide data profiles only for the 178 Census Tracts with populations over 100 persons.

City: This geographic level is for the entire District of Columbia. No comparison data columns are provided in the city profile.

PSAs: Police Service Areas (PSAs) are organized by the Metropolitan Police Department to allocate services within the city. The 56 new PSA definitions were established in 2012.

Neighborhood clusters: There are 39 neighborhood clusters throughout the city, each made up of three to five neighborhoods. Neighborhood clusters are being used by the D.C. government for budgeting, planning, service delivery, and analysis purposes.

We do not use single neighborhoods as a geography because there is a substantial amount of debate about the boundaries of single neighborhoods and these boundaries tend to change over time even where there is agreement. While the boundaries of neighborhood clusters may move over time, these are designated by the District and all boundaries and changes are publically available.

2012 Wards: The eight Council Wards are political areas used to elect members of the Council of the District of Columbia. As part of the regular redistricting process, the Ward boundaries were redrawn in 2012 based on the 2010 decennial census.

2002 Wards: The eight Council Wards are political areas used to elect members of the Council of the District of Columbia.

ZIP codes: ZIP codes are set by the U.S. Postal Service (USPS) for the purpose of facilitating the delivery of the U.S. mail. ZIP code boundaries are not fixed; they can change over time based on the needs of the USPS. Some ZIP codes do not even represent geographic areas, but rather might be assigned to post offices or other mail delivery locations. We have created profiles for the 28 most common 5-digit ZIP codes that cover Washington, D.C.

Columns

This ANC/Cluster/PSA/Tract/Ward/ZIP Code: Numbers in this column are indicator values for the geographic area listed at the top of the profile.

Average: Average values for the indicator across all geographic areas of the same type in the city (for example, the average of all neighborhood clusters, if you are looking at a neighborhood cluster profile). For an indicator like population, the value is the average (not total) population of all geographic areas of the same type. (For the total city population and other city-level indicators, access the city profile.)

Low: The lowest values of the indicators across all geographic areas of the same type (for example, all wards).

High: The highest values of the indicators across all geographic areas of the same type.

Population tab

Population and demographics

Sources: CensusCD Neighborhood Change Database (NCDB) (1980 to 2010) created by GeoLytics and the Urban Institute with financial support from the Rockefeller Foundation (2003). The NCDB is based on Decennial Census data from 1980, 1990, 2000, and 2010, and remapped to 2000 census tract boundaries. American Community Survey (ACS) is an ongoing survey administered by the U.S. Census Bureau. For more information, see the General Notes section. Decennial Census (2010). The most recent US population count. The data used in the profiles are the PL94-171 Redistricting data for the District of Columbia, released on March 24, 2011.

Population and population change are based on the Decennial Census population counts.

Children are all persons under 18 years old.

Seniors are all persons 65 years and older.

Population by Race/Ethnicity. Respondents in the decennial census are asked to identify separately both their race and their ethnicity. For Census 2000 and 2010, respondents were given a choice of six racial categories: White, Black or African American, American Indian and Alaska Native, Asian, Native Hawaiian and Other Pacific Islander, and "some other race"; and two ethnicity categories: "Hispanic or Latino" and "not Hispanic or Latino." In our neighborhood profiles, "% other race non-Hispanic" includes all persons other than White, Black or African American, and Hispanic or Latino.

For the first time with Census 2000, respondents were able to choose more than one racial category. A total of 14,661 persons in the District of Columbia (about 2.6 percent of the city's population) identified themselves as "multiracial" in Census 2000; 17,316, or 2.9 percent, in Census 2010. For comparability with earlier census years, when respondents were allowed to choose only one race, the NCDB reassigns multiracial persons to single race categories based on a series of decision rules. We used an identical process to reassign multiracial persons for Census 2010. For more details on this process, see the NCDB Data Users' Guide.

Foreign born are persons not born in the U.S. or U.S. territories; this indicator includes both naturalized citizens and residents.

% female-headed families with children is the percentage of female-headed families and subfamilies with own children (that is, children of the family head), out of all families and subfamilies with own children. Subfamilies include persons with their own children who are not the head of household. For example, a woman with her own child who lives with her mother (the child's grandmother) would be counted as a separate subfamily if the grandmother is the head of household.

Births

Sources: Vital statistics data from the D.C. Department of Health, Center for Policy, Planning and Epidemiology.

% low weight births is the percentages of total live births where the baby weighed under 5.5 pounds at the time of birth.

% births to teen mothers is the percentages of total live births to mothers who were under 20 years old.

Well-Being tab

Poverty

Sources: CensusCD Neighborhood Change Database (NCDB) (1980 to 2010) created by GeoLytics and the Urban Institute with financial support from the Rockefeller Foundation (2003). The NCDB is based on Decennial Census data from 1980, 1990, 2000, and 2010, remapped to 2010 census tract boundaries. American Community Survey (ACS) is an ongoing survey administered by the U.S. Census Bureau. For more information, see the General Notes section.

Poverty rate is the percentage of all persons living in families with incomes below the federal poverty threshold, out of persons for whom poverty status was determined. Poverty status is not determined for certain classes of people, such as those who live in institutions or other group quarters. The amount of the poverty threshold varies by family size and is adjusted annually for inflation.

% children in poverty is the percentage of all children (0 to 17 years old) living in families with incomes below the federal poverty threshold, out of children for whom poverty status was determined.

% seniors in poverty is the percentage of all seniors (65 years and older) living in families with incomes below the federal poverty threshold, out of seniors for whom poverty status was determined.

Employment

Sources: CensusCD Neighborhood Change Database (NCDB) (1980 to 2010) created by GeoLytics and the Urban Institute with financial support from the Rockefeller Foundation (2003). The NCDB is based on Decennial Census data from 1980, 1990, 2000, and 2010, remapped to 2010 census tract boundaries. American Community Survey (ACS) is an ongoing survey administered by the U.S. Census Bureau. For more information, see the General Notes section.

Unemployment rate is the percentage of all civilians 16 years and older who were not employed at the time of the decennial census and have looked for work during the previous 4 weeks (e.g. by visiting an employment agency or writing cover letters). Civilians 16 years old or older who have been given temporary layoffs and are available to work are designated as "unemployed," even if they are not seeking work. For the ACS, the definitions of employed and unemployed are based on the respondent's status during the previous week.

% pop. 16+ yrs. employed is the percentage of all persons 16 years and older who were employed in the civilian labor force or who were in the armed forces.

Education

Sources: CensusCD Neighborhood Change Database (NCDB) (1980 to 2010) created by GeoLytics and the Urban Institute with financial support from the Rockefeller Foundation (2003). The NCDB is based on Decennial Census data from 1980, 1990, 2000, and 2010, remapped to 2010 census tract boundaries. American Community Survey (ACS) is an ongoing survey administered by the U.S. Census Bureau. For more information, see the General Notes section.

% persons without HS diploma is the percentage of persons 25 years and older who have not earned a high school diploma or GED certificate.

Isolation

Sources: CensusCD Neighborhood Change Database (NCDB) (1980 to 2010) created by GeoLytics and the Urban Institute with financial support from the Rockefeller Foundation (2003). The NCDB is based on Decennial Census data from 1980, 1990, 2000, and 2010, remapped to 2010 census tract boundaries. American Community Survey (ACS) is an ongoing survey administered by the U.S. Census Bureau. For more information, see the General Notes section.

% HHs with a phone is the percentage of households that had a working telephone in their home.

% HHs with a car is the percentage of households that had one or more passenger cars, vans, and pickup or panel trucks of one-ton capacity or less kept at home and available for the use of household members.

Income

Sources: CensusCD Neighborhood Change Database (NCDB) (1980 to 2010) created by GeoLytics and the Urban Institute with financial support from the Rockefeller Foundation (2003). The NCDB is based on Decennial Census data from 1980, 1990, 2000, and 2010, remapped to 2010 census tract boundaries. American Community Survey (ACS) is an ongoing survey administered by the U.S. Census Bureau. For more information, see the General Notes section.

Family income is the total cash income from all sources for all family members; incomes are adjusted to constant dollars using the Consumer Price Index (CPI).

Public Assistance

Sources: Data on enrollment in the Supplemental Nutrition Assistance (SNAP, formerly known as food stamps) and Temporary Assistance to Needy Families (TANF) programs are provided through agreement with the D.C. Department of Human Services. Note that these are raw numbers and not percentages so cannot be directly compared with across geographies, where total populations may differ (e.g some wards are more populous than others).

Annual data provided here are averages of two monthly snapshots of program enrollment for January and July. "Persons receiving..." are persons who have applied for, and have been determined by DHS to be eligible to receive, benefits under the respective programs for the particular month. To protect confidentiality, data are suppressed if there were fewer than five persons receiving benefits in a geographic area for the year.

Reported Crimes (per 1,000 pop.)

Sources: Preliminary Part I Crimes provided through agreement with the Metropolitan Police Department (MPD), Central Crime Analysis Unit.

Data provided by MPD were tabulated by the Urban Institute for NeighborhoodInfo DC. To obtain crime rates, we divided by the Census 2000 and 2010 populations, interpolating populations in intervening years. Profiles exclude undated cases and cases for which no geography could be identified. Part I crime figures are preliminary and are subject to change due to late reporting.

Part I Crimes are particularly serious offenses that local law enforcement must report to the Federal Bureau of Investigations (FBI) on a regular basis. The FBI include these part I crimes in their Universal Crimes Report. Part I violent crimes include murder, rape, aggravated assault, and robbery. Part I property crimes include arson, burglary, larceny-theft, and motor vehicle theft.

Housing tab

Housing units, mobility, vacancy, and ownership

Sources: CensusCD Neighborhood Change Database (NCDB) (1980 to 2010) created by GeoLytics and the Urban Institute with financial support from the Rockefeller Foundation (2003). The NCDB is based on Decennial Census data from 1980, 1990, 2000, and 2010, remapped to 2010 census tract boundaries. American Community Survey (ACS) is an ongoing survey administered by the U.S. Census Bureau. For more information, see the General Notes section. Decennial Census (2010). The most recent US population count. The data used in the profiles are the PL94-171 Redistricting data for the District of Columbia, released on March 24, 2011.

Occupied housing units for 1980, 1990, 2000, and 2010 are based on the Decennial Census counts in those years.

Mobility indicators measure the extent to which housing units have changed occupants. Starting with the ACS, turnover is no longer measured over a 5-year timespan but instead reported over the previous 12 months.

Rental vacancy rate is the number of vacant-for-rent housing units divided by the total number of renter-occupied and vacant-for-rent units.

Homeownership rate is the total number of owner-occupied housing units divided by the total number of housing units.

Housing Market (Single-Family Homes)

Sources: Historical property sales file created by NeighborhoodInfo DC from extracts of the Property Owner Points data set. This data set contains points that represent the location of real property lots within the District of Columbia as well as information about the most recent property sale. Each property point is generated based on a corresponding record maintained within the D.C. Office of Tax and Revenue (OTR), Real Property Tax Administration's real property database and is provided through an agreement with the D.C. Office of the Chief Technology Officer (OCTO).

Number of sales and median sales prices are only for single-family homes, that is, condominiums, cooperatives, and multifamily apartment buildings are not included. Sales prices and changes in sales prices have been adjusted to constant dollars using the Consumer Price Index (CPI). The median sales price and price changes are not shown if there were fewer than 10 total home sales in the year for a geographic area.

Mortgage Lending (Home Purchase Loans)

Sources: Federal Financial Institutions Examination Council, Home Mortgage Disclosure Act (HMDA) data. HMDA was enacted by Congress in 1975 and is implemented by the Federal Reserve Board's Regulation C. This regulation provides public loan data that can be used to assist in determining whether financial institutions are serving the housing needs of their communities; public officials in distributing public-sector investments so as to attract private investment to areas where it is needed; and in identifying possible discriminatory lending patterns. HMDA reporting requirements apply to certain financial institutions, including banks, savings associations, credit unions, and other mortgage lending institutions. Data presented here are for home purchase loans, that is, mortgage loans secured by and made for the purpose of purchasing a dwelling, including single-family, condominium, and cooperative housing units.

Loans per 1,000 housing units are the number of mortgages issued during the year to purchase one- to four-unit homes in the specified geographic area, per 1,000 existing housing units. The count of existing housing units is from Census 2000.

Median borrower income is the median stated income for borrowers who obtained mortgages to purchase one- to four-unit homes in the specified geographic area during the year; incomes have been adjusted to constant dollars using the Consumer Price Index (CPI).

% subprime loans is the percentage of all home purchase mortgages issued by lenders determined by the U.S. Department of Housing and Urban Development (HUD) to be subprime specialists. Subprime loans are those that have higher costs (such as higher interest rates) than prime loans. Subprime loans are designed for applicants with poor credit histories, high loan-to-home-value ratios, or other credit risk characteristics that would disqualify them from lower cost, prime-rate loans. HUD classifies mortgage lenders as subprime specialists if subprime loans account for at least half of their conventional (i.e., not government-backed or insured) business. HUD also uses feedback from lenders, policy analysts, and housing advocacy groups to update the list of subprime lenders. (For more on subprime lending in Washington, D.C., and the region, visit the NeighborhoodInfo DC subprime lending web page.)

Foreclosures tab

Sources: Notices of foreclosure sale and trustee deed sale notices are obtained from the DC Recorder of Deeds. Total numbers of single-family and condominium housing units are derived from the Property Owner Points data set. This data set contains points that represent the location of real property lots within the District of Columbia as well as information about the most recent property sale. Each property point is generated based on a corresponding record maintained within the D.C. Office of Tax and Revenue (OTR), Real Property Tax Administration's real property database and is provided through an agreement with the D.C. Office of the Chief Technology Officer (OCTO).

SF homes/condos receiving foreclosure notice is the number of single-family homes and condominium units that received one or more notices of foreclosure sale during the year. A notice of foreclosure sale represents the start of the foreclosure process against a homeowner who has missed one or more mortgage payments. Note that, since November 2010, DC has instituted a foreclosure mediation program that requires an additional set of steps prior to the issuance of a notice of foreclosure sale.

Foreclosure notice rate is the number of single-family homes and condominium units that received one or more notices of foreclosure sale during the year, per 1,000 single-family homes and condominium units in the geographic area.

SF homes/condos receiving trustee deed sale notice is the number of single-family homes and condominium units that received one or more notices of trustee deed sale during the year. A trustee deed sale notice represents the end of the foreclosure process against a homeowner, resulting in the transfer home ownership to the mortgage lender or a third party.

Trustee deed sale rate is the number of single-family homes and condominium units that received one or more trustee deed sale notices during the year, per 1,000 single-family homes and condominium units in the geographic area.

For more data and informatin on foreclosures in the District of Columbia, see the NeighborhoodInfo DC foreclosure page.

Schools tab

Sources: Number of schools and audited enrollment are obtained from the Office of the State Superintendent of Education (OSSE). School and enrollment totals are based on the NeighborhoodInfo DC's Master School File. For the raw Master School File and additional documentation, see the NeighborhoodInfo DC Resources page. Enrollment totals for each level of geography reflect enrollments at schools located in each geographic area regardless of where students reside. They do not reflect the number of students living in each geographic area. Audited enrollments are checked for accuracy and represent the official figures used to make funding and policy decisions. They differ from certified enrollments, which are the raw October enrollment totals that schools report to OSSE. Audited enrollments are included in the MSF instead of certified enrollments because audited totals are independently validated and are considered the most accurate counts available.


Sources and notes updated March 31, 2015.