Updates

The following is a general description of the methodology used by EASI to update the demographic and economic characteristics for the United States, States, Counties, ZIP Codes, Census Tracts, Block Groups, and ZIP Plus 4's. The purpose of this explanation is not to divulge any proprietary methods, but to illustrate the efforts EASI has made on your behalf to create accurate updates.

More detailed information is available from several EASI PDF files:

http://www.easidemographics.com/downloads/EASI 2010 Census Update White Paper.pdf

http://www.easidemographics.com/downloads/EASI Methods - Updates.pdf

Input files

With the current release, EASI will benchmark all of the details supplied with the 2010 Census (and all related releases) at the Block Group and higher levels.

EASI has collected from the Census Bureau all current local and national updates and estimates for all the key demographic information. These official estimates have been analyzed and incorporated into our estimates and projections.

EASI has summarized from the United States Postal Service (USPS) mailable Households at a County The primary political divisions of most States are termed "counties." In Louisiana, these divisions are known as "parishes." In Alaska, which has no counties, the county equivalents are the organized "boroughs" and the "census areas" that are delineated for statistical purposes by the State of Alaska and the Census Bureau. In four States (Maryland, Missouri, Nevada, and Virginia), there are one or more cities that are independent of any county organization and thus constitute primary divisions of their States. These cities are known as "independent cities" and are treated as equivalent to counties for statistical purposes. That part of Yellowstone National Park in Montana is treated as a county equivalent. The District of Columbia has no primary divisions, and the entire area is considered equivalent to a county for statistical purposes. Each county and county equivalent is assigned a three-digit FIPS code that is unique within State. These codes are assigned in alphabetical order of county or county equivalent within State, except for the independent cities, which follow the listing of counties., ZIP Code, Census Tract, and Block Group level. These data have been used as the primary input to estimate local current change within a small area such as a Block Group. Mailable households are not the same as Census Households but are used to indicate recent change in household A household includes all the persons 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 and eat separately from any other persons 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 persons who share living arrangements. In 100-percent tabulations, the count of households or householders always equals the count of occupied housing units. In sample tabulations, the numbers may differ as a result of the weighting process. formations. These changes are combined with an EASI proprietary model for updating and forecasting at the Block Groups.

The Mailable Household A household includes all the persons 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 and eat separately from any other persons 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 persons who share living arrangements. In 100-percent tabulations, the count of households or householders always equals the count of occupied housing units. In sample tabulations, the numbers may differ as a result of the weighting process. data match starts by identifying for every ZIP Plus 4 (ZIP+4) the Block Group to which it belongs. EASI develops a split file and a plurality file of these matches using the latest Tiger® file, to determine which Block Group (primary) to which they should be assigned. One of the key goals is to identify all correct ZIP Codes and ZIP+4’s for these mailable Households and to assign them to the correct Block Group. EASI has also reconfigured the 1990 Block Groups into the 2000 Block Group configuration. An analysis of this decade change is also included in our model.

EASI has also analyzed the 2000 Census Block files in order to create a population Centroid The physical center of a selected geography. for each Block Group. The results of that analysis are used for all ring study analysis.

Data Preparation

The steps in creating the ZIP Plus 4 (ZIP+4 ) and Block Group mailable Households include:

Starting with a USPS ZIP+4 file for January 1 of the current Demographic Year which includes all valid residential ZIP+4's in the country.

For each ZIP+4, we add Census Blocks Groups based upon the Tiger® file distance formula. Approximately 20 million records are processed by this direct match (about 75% of all records).

For each remaining ZIP+4, we match against our internal geocode file (latitude and longitude). This file is based on running through address matching/geocoding A code assigned to identify a geographic entity; to assign an address (such as housing unit, business, industry, farm) to the full set of geographic code(s) applicable to the location of that address on the surface of Earth. software. Approximately 18% of total are matched to their Block Group this way.

For each remaining ZIP+4 that cannot be geocoded by the two techniques above, we use a calculated carrier route or Block Group centroid The physical center of a selected geography.. We weight the geographies to a larger area and calculate a latitude and longitude. We then determine which is the closest (distanced) Block Group. This is done for approximately 5% of the total.

If still unassigned, we use the nearest neighbor ZIP+4. Approximately 2% of the total are done through this approach (recent, 6 months-old ZIP+4s are often in this category).

Block Groups assignments are from the most recent Census Tiger® file. Tiger® errors, where identified (such as wrong FIPS Codes), have been corrected.

ZIP Plus 4's are assigned data based upon the data of the Block Group that it has been assigned to. There are no official Census Bureau data for ZIP+4.

The mailable household A household includes all the persons 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 and eat separately from any other persons 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 persons who share living arrangements. In 100-percent tabulations, the count of households or householders always equals the count of occupied housing units. In sample tabulations, the numbers may differ as a result of the weighting process. data are for residential ZIP+4's (no business-exclusive ZIP+4's are included).

Analysis

EASI has developed a series of models which use the relationship between the current mailable households at the Block Group level to estimate household A household includes all the persons 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 and eat separately from any other persons 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 persons who share living arrangements. In 100-percent tabulations, the count of households or householders always equals the count of occupied housing units. In sample tabulations, the numbers may differ as a result of the weighting process. relationships compared to the county The primary political divisions of most States are termed "counties." In Louisiana, these divisions are known as "parishes." In Alaska, which has no counties, the county equivalents are the organized "boroughs" and the "census areas" that are delineated for statistical purposes by the State of Alaska and the Census Bureau. In four States (Maryland, Missouri, Nevada, and Virginia), there are one or more cities that are independent of any county organization and thus constitute primary divisions of their States. These cities are known as "independent cities" and are treated as equivalent to counties for statistical purposes. That part of Yellowstone National Park in Montana is treated as a county equivalent. The District of Columbia has no primary divisions, and the entire area is considered equivalent to a county for statistical purposes. Each county and county equivalent is assigned a three-digit FIPS code that is unique within State. These codes are assigned in alphabetical order of county or county equivalent within State, except for the independent cities, which follow the listing of counties. and to the ZIP Code. EASI analyzes the change in relationships between these mailable households over time and compares this to the county The primary political divisions of most States are termed "counties." In Louisiana, these divisions are known as "parishes." In Alaska, which has no counties, the county equivalents are the organized "boroughs" and the "census areas" that are delineated for statistical purposes by the State of Alaska and the Census Bureau. In four States (Maryland, Missouri, Nevada, and Virginia), there are one or more cities that are independent of any county organization and thus constitute primary divisions of their States. These cities are known as "independent cities" and are treated as equivalent to counties for statistical purposes. That part of Yellowstone National Park in Montana is treated as a county equivalent. The District of Columbia has no primary divisions, and the entire area is considered equivalent to a county for statistical purposes. Each county and county equivalent is assigned a three-digit FIPS code that is unique within State. These codes are assigned in alphabetical order of county or county equivalent within State, except for the independent cities, which follow the listing of counties. and to the ZIP Code households using a proprietary formula. The analysis relates the current estimate of mailable households to the number of mailable households at the time of the 2000 Census (March 1, 2000).

One key component of the analysis is a proximity site review of all ZIP+4's based on their Block Group assignment (208,790 Block Groups). This analysis "preconditions" our input data for use in EASI demographic models.

Newly released Census county The primary political divisions of most States are termed "counties." In Louisiana, these divisions are known as "parishes." In Alaska, which has no counties, the county equivalents are the organized "boroughs" and the "census areas" that are delineated for statistical purposes by the State of Alaska and the Census Bureau. In four States (Maryland, Missouri, Nevada, and Virginia), there are one or more cities that are independent of any county organization and thus constitute primary divisions of their States. These cities are known as "independent cities" and are treated as equivalent to counties for statistical purposes. That part of Yellowstone National Park in Montana is treated as a county equivalent. The District of Columbia has no primary divisions, and the entire area is considered equivalent to a county for statistical purposes. Each county and county equivalent is assigned a three-digit FIPS code that is unique within State. These codes are assigned in alphabetical order of county or county equivalent within State, except for the independent cities, which follow the listing of counties.-level estimate information are analyzed compared to prior releases (P-25 and P-26). Annually, EASI also incorporates relevant national data as control totals. This is done for a variety of demographic factors. EASI derives this information from analysis of national data, over time, from the Annual Demographic Survey, the Current Population Survey, American Community Survey, and the Annual Housing Survey. There are also data incorporated from a variety of sources at the Census Bureau web site (www.census.gov).

ZIP Code results are independently compared to the USPS current ZIP Code file of residential deliveries. Additional updating sources include: USPS AMS files and Postal bulletins (the ZIP Alert); these record any annual changes that take place to ZIP codes, including name changes and delivery or branch changes, as they become official. Other sources include: U.S. Postal Service City-State File (monthly) and Delivery Statistics File. These datasets incorporate the main inventory of ZIP Codes and the individual post office and other names associated with them. Each year EASI conducts a complete review of these files to maintain a current ZIP Code roster. EASI inventories the old ZIP Codes as well.

Updates to the current year and a 5-year projection are carried out for the United States level and for key variables at the county The primary political divisions of most States are termed "counties." In Louisiana, these divisions are known as "parishes." In Alaska, which has no counties, the county equivalents are the organized "boroughs" and the "census areas" that are delineated for statistical purposes by the State of Alaska and the Census Bureau. In four States (Maryland, Missouri, Nevada, and Virginia), there are one or more cities that are independent of any county organization and thus constitute primary divisions of their States. These cities are known as "independent cities" and are treated as equivalent to counties for statistical purposes. That part of Yellowstone National Park in Montana is treated as a county equivalent. The District of Columbia has no primary divisions, and the entire area is considered equivalent to a county for statistical purposes. Each county and county equivalent is assigned a three-digit FIPS code that is unique within State. These codes are assigned in alphabetical order of county or county equivalent within State, except for the independent cities, which follow the listing of counties. level, as well. Block Group (BG) level estimates are all controlled to the county The primary political divisions of most States are termed "counties." In Louisiana, these divisions are known as "parishes." In Alaska, which has no counties, the county equivalents are the organized "boroughs" and the "census areas" that are delineated for statistical purposes by the State of Alaska and the Census Bureau. In four States (Maryland, Missouri, Nevada, and Virginia), there are one or more cities that are independent of any county organization and thus constitute primary divisions of their States. These cities are known as "independent cities" and are treated as equivalent to counties for statistical purposes. That part of Yellowstone National Park in Montana is treated as a county equivalent. The District of Columbia has no primary divisions, and the entire area is considered equivalent to a county for statistical purposes. Each county and county equivalent is assigned a three-digit FIPS code that is unique within State. These codes are assigned in alphabetical order of county or county equivalent within State, except for the independent cities, which follow the listing of counties. control totals. That is, the Block Group data will add to the separately generated county The primary political divisions of most States are termed "counties." In Louisiana, these divisions are known as "parishes." In Alaska, which has no counties, the county equivalents are the organized "boroughs" and the "census areas" that are delineated for statistical purposes by the State of Alaska and the Census Bureau. In four States (Maryland, Missouri, Nevada, and Virginia), there are one or more cities that are independent of any county organization and thus constitute primary divisions of their States. These cities are known as "independent cities" and are treated as equivalent to counties for statistical purposes. That part of Yellowstone National Park in Montana is treated as a county equivalent. The District of Columbia has no primary divisions, and the entire area is considered equivalent to a county for statistical purposes. Each county and county equivalent is assigned a three-digit FIPS code that is unique within State. These codes are assigned in alphabetical order of county or county equivalent within State, except for the independent cities, which follow the listing of counties. data. Other geographies are summarized from the Block Group level. BGs are added together to create Census Tracts and parts of BGs are added together to get ZIP Codes and cities.

Consistency - year to year changes.

Each year EASI uses all available sources to maintain the highest quality in our estimates. Sometimes the new information will make year-to-year changes less meaningful. For instance, a 2002 ZIP Code may have a different definition of BGs because of postal changes in the last year. The changes from our 5 year forecast, within an EASI calendar year, are consistent from the current estimate, but changes from last year's estimates are not necessarily so. EASI geography estimates are all based on the same geography, that is, all ZIP Code estimates for April 1, 1990,; April 1, 2000, January 1, 2003; and January 1, 2008 are all based on the same geographic definition.

Other issues of consistency relate to release of Census data and new definitions of variables. For example, the 2000 Census has a new Race question (e.g. White Includes persons who indicated their race as "White" or reported entries such as Canadian, German, Italian, Lebanese, Near Easterner, Arab, or Polish. Alone, Black Alone, Asian In EASI products Asian population and households include both Asian and Pacific Islander. Alone, etc.) which allows for multiple races and is not compatible with previous estimates.

Another factor in consistency is that with some data sources become available annually, but others may be released only once every two or three years. Post-Census estimates are also subject to revision for several reasons. Occasionally a sample size can be expanded to allow for more detailed results. Another change could be that the sample is framed against any new data such as the 2000 Census. EASI, with decades of experience, analyzes all of the information and incorporates the results into our estimates if it will contribute to the quality of our information.

ZIP Code Details

ZIP Codes are especially difficult for consistency from year to year, even it they appear to be the same 5 digits. Since each ZIP Code area may change from year to year, EASI spends considerable effort to develop new ZIP Code data for each year. EASI assigns a portion of each Block Group to a ZIP Code based on the latest information for each year (1990, 2000, current and five year forecast) in order to assure consistency. EASI creates a proprietary ZIP to Block Group (partial) analysis annually and allocate all land area necessary to create a ZIP Code.

Income Definition

There are many different definitions of income that are available for analysis. EASI income models are based on race and family A group of two or more people who reside together and who are related by birth, marriage, or adoption. characteristics to obtain a current estimate. If EASI estimates are compared to other sources such as Disposable Income or Total Personal income, they may differ.

Consumer Expenditure Survey (CEX)

The results of the CEX are analyzed annually by EASI and combined with EASI estimates at the Block group level. The Bureau of Labor Statistics and the Bureau of the Census conduct the CEX. There are two parts to the survey. The first part is a diary, which is completed by respondents for two consecutive one-week periods. The second part is an interview survey conducted quarterly (every three months) for five quarters. The interview survey includes roughly 95% of all expenditures and includes large expenditures such as property, automobiles, major appliances, rent, utility payments, insurance premiums, and others.

EASI annually models these results of 530+ categories of expenditures against our updated demographic estimates. EASI's models use our own BG demographic estimates to update these potential sales.

Retail Sales and Store Groups

EASI's Retail Sales Estimates include Food Service – Total Retail Sales (the standard 12 major stores plus Food Service). All data are based on an extensive review of County The primary political divisions of most States are termed "counties." In Louisiana, these divisions are known as "parishes." In Alaska, which has no counties, the county equivalents are the organized "boroughs" and the "census areas" that are delineated for statistical purposes by the State of Alaska and the Census Bureau. In four States (Maryland, Missouri, Nevada, and Virginia), there are one or more cities that are independent of any county organization and thus constitute primary divisions of their States. These cities are known as "independent cities" and are treated as equivalent to counties for statistical purposes. That part of Yellowstone National Park in Montana is treated as a county equivalent. The District of Columbia has no primary divisions, and the entire area is considered equivalent to a county for statistical purposes. Each county and county equivalent is assigned a three-digit FIPS code that is unique within State. These codes are assigned in alphabetical order of county or county equivalent within State, except for the independent cities, which follow the listing of counties. and ZIP Code Retail Trade data for 1997. EASI created a file of benchmark data from the released Census data which is used for our annual update.

Each year, re-benchmarks estimates for each update to a new set of Block Group estimates for all retail categories. These estimates are based on our current analysis of the latest NAICS employment data for each retail store and food service. EASI resolves any inconsistencies between sources as part of this annual process.

The 13 store groups that comprise Total Retail Sales are:

1. Motor Vehicle and Parts Dealers

2. Furniture and Home Furnishings Stores

3. Electronics and Appliance Stores

4. Building Material and Garden Equipment and Supplies Dealers

5. Food and Beverage Stores

6. Health and Personal Care Stores

7. Gasoline Stations

8. Clothing and Clothing Accessories Stores

9. Sporting Goods, Hobby, Book, and Music Stores

10. General Merchandise Stores

11. Miscellaneous Store Retailers

12. Nonstore Retailers

13. Food Services