Why Nielsen Data?
What sets Nielsen apart as the demographic industry leader?
- Methodology for Creating Demographic Estimates
- Creating Small-Area Population and Household Estimates
- Local Input Source Used to Create Small-Area Population and Household Estimates
- Substantive Methodology Enhancements Developed by Nielsen
- R&D Resources Committed to Demographic Estimates
- The Most Accurate Demographic Estimates
- Preparation of Estimates for Nonstandard Geographic Areas
- Identification and Estimation of Very Rapid Growth for Tracts
- Impact of Military Base Closings and Catastrophic Events
- Full Cross-Tabulation Provided by Age by Sex by Race by Hispanic or Latino
- Age Breaks for Age/Sex Estimates
- Nielsen's Demographic Estimates Experience and Credentials
Methodology for Creating Demographic Estimates
Nielsen has documented its methodology in a comprehensive paper detailing the methods used to estimate small (local) area demographics. This document is updated on a yearly basis by the demographers that produce the estimates and projections so that the most recent Update methodology is always available to you. We believe that disclosure of these methods is essential to the data users' understanding of the estimates produced.
Nationwide sets of small area demographic estimates and projections were pioneered by the private sector 30 years ago, and such updates are still a unique product of the private suppliers. These suppliers have developed a variety of approaches to annual demographic estimation, and the results for small areas can vary widely. Users are encouraged to familiarize themselves with the methods used to produce such data.
For more information regarding Census 2000 and Nielsen products, visit our special Census website.
Creating Small-Area Population and Household Estimates
Nielsen adapts standard demographic methods to use with the best data at each geographic level. For example, Nielsen tracks neighborhood-level growth and decline from the annual acquisition of current small-area data from across the nation. Sources include estimates from local governments, consumer database counts, and postal delivery statistics. Such sources allow a "bottom-up" methodology grounded in authoritative local sources. Nielsen also uses Census Bureau estimates and other federal data to produce highly accurate totals for larger areas such as cities, counties and states. These independent estimates are used as control totals for the small area estimates, thus providing the internal consistency of a "top-down" process. Nielsen has refined this approach over the past three decades and annually evaluates new data sources and techniques to ensure maximum accuracy.
Local Input Source Used to Create Small-Area Population and Household Estimates
The best demographic estimation methods are only as good as the data used as input, so the selection and incorporation of accurate input is critical at all geographic levels. At the census tract and block group levels, the Nielsen method measures change based on sources including local estimates, Donnelley Marketing database trends, counts from the Equifax TotalSource database and the Equifax Consumer Marketing Database, and United States Postal Service (USPS) delivery statistics.
For the current year, national and state estimates were based on Census Bureau estimates. County estimates were based on Census Bureau estimates, combined with state-produced county estimates in selected states. At the tract and block group levels, post-2000 trends were based on local estimates and post 2000 trends in USPS address counts and TotalSource consumer database households. Each year, the Demographic Update Methodology lists the numerous resources incorporated into the Update, and explains how Nielsen uses those data in the estimation process.
Substantive Methodology Enhancements Developed by Nielsen
Nielsen continually strives to improve its methods for creating demographic estimates. Some of the substantive enhancements include:
- Age/sex/race/Hispanic-specific application of cohort survival methods – with important refinements to the cohort survival assumptions.
- Estimation of population by single year of age (0 – 100+). This kind of detail makes custom age breaks a simple process of addition rather than error-prone percentaging.
- Introduction of post-census input data in areas where local estimates are not available. Important sources used in the past and being developed for post-2000 include Equifax, Donnelley Marketing, USPS, and the Census Bureau's American Community Survey.
- The Rapid Change Review: Nielsen gives individual attention to tracts where post-census sources indicate very rapid change since the most recent census. This process is greatly enhanced by the crosscheck capability provided by having multiple sources in many areas.
- A procedure for estimating the impact of military base closings and natural disasters such as floods, hurricanes, and fires.
- Use of post-census input data directly at the block group level.
R&D Resources Committed to Demographic Estimates
Nielsen' commitment to research and development is evident in its expert demographic staff and data acquisition investment. The Nielsen methodology and resources for demographic estimates integrates the strengths of several previously competitive programs, now part of the Nielsen/VNU family, including National Planning Data Corporation, Donnelley Marketing Information Services (DMIS), National Decision Systems (NDS), Market Statistics and Nielsen. Through these acquisitions, Nielsen has gained a great deal of experience and knowledge about the production of demographic estimates. Many of the staff that led these programs now collaborate on the Demographic Update as Nielsen staff. This gives Nielsen the combined methods and resources of several companies, plus decades of cumulative experience and expertise.
The Most Accurate Demographic Estimates
The opportunity to evaluate the accuracy of small-area estimates comes only once every 10 years when the new census results become available. Unlike many data suppliers, Nielsen has conducted such evaluations and made available papers that substantiate the accuracy of our 1990 and 2000 estimates when compared to the respective census counts. Only Nielsen can cite results from a 1980 evaluation – the industry's first evaluation of nationwide small-area estimates. In short, we put our numbers to the test whenever possible and often make the results available. Because the demographic estimation process requires considerable skill, expertise, and ongoing evaluation, and because the results will have significant impact on the marketing decisions you make, we encourage you to review the Update Methodology.
Preparation of Estimates for Nonstandard Geographic Areas
The methods used to prepare estimates for nonstandard areas, such as postal, media, communications, and other industry geographies, are different from those used to create estimates for census geographies. Estimates for nonstandard geographies are created as reconfigurations of already completed block group estimates. These geographic estimation processes are distinct from, and should not be confused with, demographic estimation methods.
Identification and Estimation of Very Rapid Growth for Tracts
Nielsen knows that rapid population and household growth at the tract and block group levels can take place over the course of a year. Because this growth can affect your market significantly, we put our small-area input data through a "rapid change review." Our demographers manually review any tract where the input data indicate a change in growth beyond an established threshold. Before estimating exceptional growth, tracts are reviewed and crosschecked with other input data to rule out spurious indications of growth.
Impact of Military Base Closings and Catastrophic Events
Using data from the Defense Manpower Data Center, Nielsen estimates the impact of military base closings and realignments at the tract level. A concerted effort is made to build the impacts of events such as fires, hurricanes, and floods into our estimates at the tract level. We do so through the use of our tract level sources guided by consultation with local demographers.
Full Cross-Tabulation Provided by Age by Sex by Race by Hispanic or Latino
Nielsen estimates the full cross-tabulation of population by age by sex by race by Hispanic or Latino.
Age Breaks for Age/Sex Estimates
Nielsen can provide age/sex estimates for single years of age from 0 – 100+ years. This yields the most accurate estimates for custom age distribution requests.
Nielsen' Demographic Experience and Credentials
It is important to realize that while nationwide block group estimates have become routine in the information industry, they are unheard of outside the industry. Over the years, Nielsen demographers have advanced both the methods of private sector demography and its reputation. These gains owe much to professional activity, including the evaluation of census-year estimates, the innovative incorporation of new data sources and the candid presentation of methods in professional papers. The Nielsen demographers chart new territory every time they produce an annual Update, and by representing their work responsibly within their profession, they gain recognition for advancing the science and art of applied demography.
Nielsen' professional involvement extends beyond the demographic estimates. Nielsen demographers regularly attend professional conferences, present on a variety of topics, and serve on professional panels addressing issues of importance to all data users. They maintain a close working relationship with the Census Bureau, having contributed to the planning of the 2000 census and participating in the planning of the 2010 census through involvement in professional panels and census advisory committees.
