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Data guide

This site pulls data from national and Vermont-based sources, including the U.S. Census Bureau, Vermont Department of Taxes and the U.S. Department of Housing and Urban Development. Each visualization on the site contains a description of its content and a source for the data.

Datasets are vetted, compiled, and analyzed by the VHFA research team to assess data quality and to improve access to available housing data for all Vermonters.

Each visualization on the site provides a description of the data source and will provide definitions for key terms used within the page. Expand the tabs below for more information about selected data sources and useful data definitions:

U.S. Census Bureau

The U.S. Census Bureau provides two data sources used on this site: The U.S. Decennial Census and the American Community Survey (ACS).

Survey details

The Decennial Census is conducted once every ten years, and is intended to survey all households in the United States. The ACS is conducted continuously, and samples a smaller number of households to develop estimates for the population. ACS surveys collect more detailed information previously only available in the long-form Decennial Census, which ACS has replaced since 2005.

ACS data on the Vermont Community Profiles are obtained or derived from the ACS 5-year rolling estimates. For example, the 2016 ACS estimates are derived from surveys completed between 2012 and 2016. Although some of the Vermont Community Profile visualizations allow users to compare ACS estimates from different years, the Census Bureau cautions users about identifying year-to-year trends if estimates are based on overlapping 5-year periods.

Understanding estimates and data reliability ratings

American Community Survey (ACS) estimates are accompanied by margins of error. The margin of error describes the amount of sampling error associated with a particular estimate resulting from the survey. The larger the margin of error relative to the value of the estimate, the less confidence we have that the estimated results are close to the true figures for the population. Some ACS data sets shared on the Vermont Community Profiles may have very large margins of error, especially for communities with small populations, or for small subsets of a population, due to the small sample size. Furthermore, it should be noted although the ACS is administered by trained professionals and questions are vetted thoroughly, the estimates rely on data reported by survey respondents, which could contain inaccuracies.

Note that since the Decennial Census is a count, there are no margins of error available. However, since the Census is a count of the actual population, the data is expected to be very reliable.

To help users make informed decisions when using the data on the profiles, we have developed a simple system of data reliability ratings to accompany ACS data points. These ratings are displayed when users hover over data points on the visualizations. The data reliability ratings are derived from the coefficient of variation (CV) between the ACS estimate and its margin of error. If the CV is less than or equal to 15, the data reliability rating is “Good”. CV's less than or equal to 30 are labeled “Fair”, and CV's greater than 30 are labeled “Use with caution”.

If a user encounters a data reliability rating of “Use with caution”, users are encouraged to critically evaluate whether the data seems plausible. Users can compare estimates with previous years, with neighboring geographies, or with county-level estimates where appropriate.

More resources

The U.S. Census Bureau publishes the guide Understanding and Using American Community Survey Data: What All Data Users Need to Know, which contains a more detailed overview on how ACS data can be used and how to judge the accuracy of ACS estimates. The Bureau also provides a Statistical Testing Tool for users who want to compare two ACS estimates.

At the bottom of each visualization we provide a short description of the relevant terms. For a more detailed description of survey terms, review the ACS 2019 Subject Definitions. Users can also access a copy of the 2019 ACS Survey to view how the questions were administered to survey respondents. Be aware that although the U.S. Census Bureau tries to keep the ACS as consistent as possible, some subject definitions have evolved over the years.

A full list of all ACS tables is also available from the Census Bureau.

Housing units

The Decennial Census and American Community Survey use households to collect data. According to the U.S. Census Bureau, a household includes all the people who occupy a housing unit. A housing unit is a house, an apartment, a mobile home, a group of rooms, or a single room that is occupied (or if vacant, is intended for occupancy) as separate living quarters. Separate living quarters are those in which the occupants live separately from any other people in the building and which have direct access from the outside of the building or through a common hall. The occupants may be a single family, one person living alone, two or more families living together, or any other group of related or unrelated people who share living arrangements.

A housing unit is classified as occupied if it is the current place of residence of the person or group of people living in it at the time of interview, or if the occupants are only temporarily absent from the residence for two months or less, that is, away on vacation or a business trip. If all the people staying in the unit at the time of the interview are staying there for two months or less, the unit is considered to be temporarily occupied and classified as “vacant.”

Point in Time (PIT) Count

The Point-in-Time (PIT) Count is an annual survey of people experiencing homelessness, conducted in all communities in the United States. Through a coordinated effort, housing support agencies aim to interview all people who meet the federal definition of “literal homelessness” on a single day in January, whether they are unsheltered or temporarily sheltered in places such as emergency housing, a publicly funded hotel room, or transitional housing.

Since 2007, the U.S. Department of Housing and Urban Development (HUD) has required all states to conduct an annual PIT Count to continue receiving funds for homelessness assistance. The resulting dataset is the only comprehensive view of people experiencing homelessness in the United States over time. The survey is conducted annually during the last week of January – the data does not show how many people are entering and exiting homelessness in an area over the year, instead focusing on accurately recording the instances of homelessness on the night of the survey.

The survey is administered across the country by local housing service providers through a coalition model known as the Continuum of Care (CoC). According to HUD, “A CoC consists of a partnership of service & resource providers, housing developers, state agencies, and others in the homelessness or low-income service system in a geographic region. CoCs monitor and address housing and service gaps through proactive solutions and manage annual funding from the US Department of Housing & Urban Development.”

Vermont has two HUD-recognized Continua of Care (CoCs): the Chittenden County Homeless Alliance (CCHA) which covers Chittenden County and the Vermont Balance of State CoC (VT BoS CoC) that encompasses the other 11 counties. Each region in the state also has a local group focused on regional homelessness prevention and intervention efforts. These groups were formerly called Local CoCs and are now called Local Housing Coalitions.

During the COVID-19 pandemic, Vermont’s homelessness response network dramatically changed as congregate shelters were closed to stop the spread of the virus. In response, the state Agency of Human Services (AHS) expanded access to the General Assistance Emergency Housing Program allowing more Vermonters experiencing homelessness to temporarily stay in a hotel room with state funding. This transitional housing program ended after the PIT 2023 count was conducted, suggesting that further fluctuation should be expected in the 2024 data.

The results of PIT are likely an under-count of the true instances of homelessness in a community. Collecting the data is highly resource intensive, requiring the coordination of many agencies attempting to reach some of the most marginalized Vermonters. The data is reliant on housing support workers and volunteers counting and interviewing people sleeping in unsheltered locations during the January weather. Vermont consistently has a much greater portion of people in temporary shelter during the survey than people who are fully unsheltered. The count also does not include people imminently at risk of homelessness or who may be living somewhere temporarily (couch surfing or staying with family) as the data would be too difficult to collect.

For more information about homelessness in Vermont, visit the VCEH (now known as Housing & Homeless Alliance of VT) and CCHA websites or attend Homelessness Awareness Day held every year in Montpelier in January.

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