True Cost Tompkins Frequently Asked Questions
Thank you for visiting True Cost Tompkins! This page will answer many of your general and specific questions.
Where does this data come from?
The data used for the True Cost Tompkins map was gathered and processed by the Center for Neighborhood Technology (CNT). The Center for Neighborhood Technology is a nonprofit research and advocacy organization committed to improving urban economies and environments across the United States through researching and analyzing urban problems, testing and promoting economically efficient and environmentally sound solutions, and demonstrating the value of investing in sustainable solutions.
The data used in this project is part of the H+T Index (Housing + Transportation) developed by CNT. The Center for Neighborhood Technology’s Housing and Transportation Affordability Index provides a comprehensive way of thinking about the true affordability of place. It presents housing and transportation data as maps, charts and statistics for 917 metropolitan and micropolitan areas—covering 94% of the US population. Costs can be seen from the regional down to the neighborhood level.The H+T Index was originally created in 2006 and has been through multiple improvements since then, the most recent dataset is from 2015.
Is this data really relevant for Tompkins County?
Despite being a national project, the data used by the Center for Neighborhood Technology in the H+T Index is mostly hyper local. The data is derived from US Census surveys the American Community Survey of local households as well as Consumer Expenditure Surveys, The True Cost Tompkins team spent many hours testing the data and model developed by CNT against other local data sources and found it to be consistent.
The complete 2015 updated H+T Index methodology and data sources report can be found at http://htaindex.cnt.org/about/HT_Index_Methods_2013.pdf
What are block groups and why is the data combined at this level?
The data displayed in the True Cost Tompkins web map is based on averages for block groups. The US Census combines several blocks into a block group intended to have a population of around 1500 people, though populations vary from a few hundred to around 3000. Census block groups are the smallest level at which financial data is available from the US Census; data is collected from individual households, but for privacy reasons only shared lumped together.
Unfortunately, in rural areas block groups cover a very large area. The Town of Ulysses, for example, has only 2 block groups, while the City of Ithaca has XX. In a rural context, a single block group may contain very disparate neighborhoods from multi-million dollar lake houses to trailer parks. Working with average data in this situation does not show a complete picture for any individual family, however it is useful for understanding broad planning questions at the town, village, and county level.
What do you mean by “affordable”?
Affordability in our context means a household spends 30% or less of their income on housing and 15% or less of their income on transportation, or a combined 45% or less of their income on housing and transportation combined. This is a generally accepted affordability metric used by government agencies like the federal department of Housing and Urban Development (HUD). Generally, if a household exceeds these amounts, they can’t afford things like medical insurance, life insurance, retirement and other savings, and other unexpected or infrequent expenses. However, everyone’s situation is different, and things like student loans, credit card payments, or other unusual family costs may make even 45% of income for housing and transportation a burden.
How was the 45% affordability benchmark developed? How does it differ from the traditional view of affordability?
Traditionally, a home is deemed affordable if its costs are no more than 30% of a household’s income. This measure, however, ignores transportation costs—typically a household’s second-largest expense—which are largely a function of the household’s location. Based on research in communities ranging from large cities with extensive transit to small micropolitan areas with extremely limited transit options, CNT has found that 15% of the Area Median Income (AMI) is an attainable goal for transportation affordability. By combining this 15% level with the 30% housing affordability standard, CNT recommends a new view of affordability, one in which combined housing and transportation costs are no more than 45% of household income.
What is location efficiency?
Just as buildings can be energy efficient, neighborhoods can be location efficient. Compact neighborhoods with walkable streets, access to jobs and transit, and a wide variety of stores and services have high location efficiency. They require less time, money and greenhouse gas emissions for residents to meet their everyday needs.The savings of location efficiency add up for households and communities. Transportation costs are 8% of household income in location-efficient neighborhoods or over 26% in inefficient locations. Greenhouse gas emissions also fluctuate, depending on household reliance on costly, carbon-intensive automobile travel.
For a general overview of how these numbers were measured visit: http://htaindex.cnt.org/about/
How are housing costs derived?
CNT (or True Cost Tompkins) does not derive housing costs. Housing costs come directly from the American Community Survey and are calculated as the average of Median Selected Monthly Owner Costs and Median Gross Rent scaled by the percentage of owner-occupied housing units with a mortgage, and renter-occupied housing units with cash rent. To get deeper into the details you can read all the specifics at http://htaindex.cnt.org/about/HT_Index_Methods_2013.pdf
How are transportation costs derived?
The unique value of CNT’s H+T® Index is the transportation cost model. Several characteristics of the built environment are used to model transportation costs, including gross density, block density, and percent of single family homes. The model also employs six measures developed by CNT: the Regional Household Intensity (a household gravity measure), Employment Access Index (a measure of job opportunity), Employment Mix Index, Transit Connectivity Index (a measure of transit access), Transit Access Shed (a measure of the area accessible within a 30-minute transit trip), Jobs Accessible in 30 Minute Transit Ride (the number of jobs in the TAS area), and Average Available Transit Trips per Week (frequency of service). For specifics please see the Methodology section. http://htaindex.cnt.org/about/HT_Index_Methods_2013.pdf
In addition to the standard data sources CNT also included local travel demand forecasting and TCAT ridership data in modeling transportation costs in Tompkins County including data from TCAD, modal split and inter-county travel data developed by DSS, and County Planning Document.
Are taxes, maintenance and utilities included in the cost of housing?
Housing costs for owners include: mortgage payments, real estate taxes, property insurance, utilities, fuels, mobile home costs and condominium fees. For renters, costs amount to contract rent plus the estimated average monthly cost of utilities and fuels.
What is a “Average Income Household” and why is affordability reported from this perspective?
The Average Income Household is synonymous with CNT’s “Regional Typical Household” which assumes a household income that is the median income for the region, the average household size for the region and the average commuters per household for the region. In the case of communities in Tompkins County, the region is Tompkins and Cortland Counties. An important aspect of the H+T Index is that transportation costs are modeled for the "typical" household in a region, or the household represented by these three values.By fixing income, household size and commuters, the model controls for the impact of these variables on transportation costs. Differences in transportation costs are therefore a result of neighborhood characteristics and variation in the built environment. When variables are shown as a percent of income, this median income value is used. Therefore, the variable can be interpreted as the cost impact of a given location on the average household in the region.True Cost Tompkins uses CNT modeled data for two household types:Average Income Household, with its assumptions described above.Moderate Income Household, which assumes a household income of 80% of the regional median, the regional average household size and the regional average commuters per household.
Why does the Regional Typical Household have fractions of people and commuters?
The Regional Typical Household takes into account all types of households in the region, and does not represent a specific household, but an average of all households. Every region has a unique mix of households: two-commuter households, single-earner households, adults with no children, single people, etc. - so the Regional Typical Household represents a composite of the broad range of households within the Tompkins-Cortland region.Using a typical or representative household, and estimating travel behavior and costs for this representative household, the H+T Index provides a valuable measure of place. By keeping the household metrics constant, the differences in these modeled costs represent changes in behavior that are induced by the place and its environment, and not by the various households living in each neighborhood.
How is walkability measured?
Measures of street connectivity have been found to be good proxies for pedestrian friendliness and walkability. Greater connectivity between streets creates smaller blocks and tends to lead to more frequent walking trips. The model uses average block density as a proxy measure for walkability.How are regions defined?The regions used in the H+T Index correspond to the Core Based Statistical Areas (CBSA) defined by the Office of Management and Budget (OMB) for use by federal statistical agencies in collecting, tabulating, and publishing national statistics. The term Core Based Statistical Area (CBSA) is a collective term for both metropolitan and micropolitan areas. The Region for Tompkins County data is the Ithaca Core Based Statistical Area which is a combination of Tompkins and Cortland Counties.
Is the cost of parking considered in the model?
The model does not currently incorporate the cost of parking and other miscellaneous transportation expenses, including tolls and taxis.Why are auto costs different than previous versions of the H+T Index?Previous versions of the H+T Index used auto ownership costs from AAA’s Your Driving Costs, which is one of the most widely used measures of costs for owning and operating a vehicle. It is employed by government agencies, industry experts and transportation consultants and is based on amortized purchase costs for the first five years of a newly purchased auto and includes per mile costs for maintenance, repairs and fuel. This version of Index uses costs derived from the Consumer Expenditure Survey (CES) in order to derive a more representative measure of costs for autos up to 10 years old. These costs are a product of research commissioned by the Department of Transportation (DOT) and the Department of Housing and Urban Development (HUD).
How are greenhouse gas emissions calculated?
To calculate greenhouse gas emissions, vehicle miles traveled (VMT) is modeled for the local household. The local household differs from the regional typical household in that income, household size and commuters per household are not fixed and reflect the average for households living in each block group. These figures come directly from the American Community Survey. A standard emissions factor of 0.438 metric tonnes of CO2 per mile is then applied to the local VMT estimates to get the emissions figure.
How can I compare two different maps?
The H+T Index website http://htaindex.cnt.org/map/ has several map comparisons beyond what is available on the True Cost Tompkins website (Location Affordability, Greenhouse Gas Emissions). In addition to the H+T Index single-map view where all the available variables can be mapped. Options to view other map comparisons include: opening two tabs with H+T Index single-map views, printing out the maps of interest, or downloading the block group level data and creating your own maps.
Is the H+T Index data available for download?
Yes, the model outputs and built environment variables are available for free download on the CNT Data page http://htaindex.cnt.org/download/ . Transit and greenhouse gas variables, as well as longitudinal and custom datasets, are available for purchase. If you are interested in data beyond what is available there, please contact Linda Young (firstname.lastname@example.org).
Last updated August 8, 2017