I previously requested help calculating median family income using the Pareto Interpolation. I appreciate the replies. The attached spreadsheet contains the median family income for towns in South Western Connecticut. The top table shows the values calculated by Pareto Interpolation, and the bottom table illustrates the values calculated by Linear Interpolation. I also calculated the percentage difference between the calculated values and the official Census figures. I confirmed that the difference between the Pareto figures and the Census figures are most likely due to the fact that the Census Bureau calculates median value based upon more detailed distribution information than it releases to the public. Notice that the Pareto calculations are sometimes higher and lower than the official figures, but the linear calculations are higher. Most likely this observation is because Pareto uses a logarithmic curve rather than a straight line. (There may be a few instances where the Pareto figure would be higher than linear.) In addition, the Pareto calculations tend to be more accurate than the Linear ones. I believe the spreadsheet provides a good way to estimate median income values for regions that are not tabulated by the Census. USE AT YOUR OWN RISK. I am not a statistician, and I only have a limited understanding of the formulas. Good luck, Daryl
--
Daryl Scott
South Western Regional Planning Agency
Stamford Government Center
888 Washington Blvd., 3rd Floor
Stamford, CT 06901
Tel: (203) 316-5190
Fax: (203) 316-4995
E-mail: dscott(a)swrpa.org
From: "Census2000" <census2000(a)ccmc.org>
Supreme Court Upholds Imputation Method In Utah Apportionment Case
In a close (5 4) decision issued this morning, the United States
Supreme Court upheld the Census Bureaus use of imputation to count
some people who census takers cannot reach through direct enumeration
methods. Utah filed a lawsuit last spring, arguing that the statistical
method violated both the Census Act and the Census Clause of the U.S.
Constitution, and deprived it of a fourth congressional seat that
instead went to North Carolina. North Carolina, which picked up a 13th
congressional seat after the 2000 census, intervened in the case in
support of the Census Bureau.
The Supreme Court ruled that imputation does not violate either section
195 of title 13, United States Code (the Census Act), or the
Constitutions requirement for an enumeration of the population every
ten years for the purpose of congressional apportionment. Justice
Stephen Breyer authored the majority opinion in Utah et al. v. Evans,
Secretary of Commerce, et al. (01-714), in which Chief Justice William
Rehnquist and Justices John Paul Stevens, David Souter, and Ruth Bader
Ginsburg joined. Justice Sandra Day OConnor joined Parts I and II of
the majority opinion, and filed an opinion concurring in part and
dissenting in part. Justice Clarence Thomas also filed an opinion
concurring in part and dissenting in part, in which Justice Anthony
Kennedy joined. Justice Antonin Scalia wrote a dissenting opinion.
Hot-deck imputation involves the use of scientific models to assign
occupants (or vacancy status) to housing units from which a mailed
questionnaire was not returned and census takers were unable to find any
residents after six visits. The Census Bureau assigns the number of
occupants based on information collected from a similar, nearby housing
unit. Imputation added roughly 1.2 million people in 620,000 housing
units (less than one-half of one percent of the national population) to
the state population totals used for congressional apportionment. (For
some households, imputation is used to fill in missing characteristics,
such as race, or to add occupants who are not listed on a census form
but for whom there is some evidence of residency. A National Academy of
Sciences panel reported last fall that Census 2000 included 5.8 million
imputations, a disproportionate number of which involved racial
minorities, renters, and children.) The bureau first used the method in
the 1960 census. Indiana unsuccessfully challenged the technique after
the 1980 census, when it lost a House seat to Florida based on imputed
population.
In oral arguments before the Supreme Court on March 27, Utahs lead
counsel, Thomas Lee, described imputation as a form of sampling that the
Court struck down in 1999 (Department of Commerce v. U.S. House of
Representatives, 526 U.S. 316). In the earlier case, a 54 majority of
the Court ruled that the Census Act barred the use of sampling to
compile the state population totals used for congressional
apportionment. In todays ruling, the Court noted that imputation
differs from sampling in several ways. Sampling involves extrapolating
the characteristics of a large group of people from a small one, the
Court wrote, while imputation seeks only to fill in missing data for
particular housing units, using information from similar housing units
that are not chosen randomly. The methodological differences place
imputation outside the scope of section 195, which refers only to
sampling (in quotations in the law), the majority concluded. The
Court suggested that Congress knew about the use of imputation when it
amended the Census Act in 1976 to prohibit sampling in deriving the
apportionment counts, inferring that sampling, as used in the statute,
was a term of art.
The Court also held that hot-deck imputation does not violate Article I,
section 2, of the Constitution (the Census Clause), which calls for a
census every ten years in such manner as [Congress] shall by Law
direct. The majority rejected Utahs contention that the
Constitutions reference to an actual Enumeration requires the Census
Bureau to count every person directly. Instead, the term actual
referred to apportionment of the Third Congress (which would be seated
after the first census was conducted), while apportionment of the First
and Second Congresses was based on conjecture as to the population of
the states then in existence, the Court said. The majority also pointed
to other methods the Census Bureau has used since 1800 to add missing
people to the count, including asking neighbors, landlords, and postal
workers to supply information about households that failed to respond to
the census.
The Court said it was not deciding the precise methodological limits
of the Census Clause. However, the use of imputation in this case was
part of an effort to reach every household, represented methods of
inference rather than statistical sampling, involved a tiny percent
of the total population, was not likely to be subject to manipulation,
and was an alternative to a far less accurate assessment of the
population, and therefore did not exceed the Constitutions limits, the
majority concluded.
In addition, the Court rejected North Carolinas argument that Utah
lacked legal standing to challenge imputation or other counting
methods after the census was completed. North Carolina had asserted
that statutes governing apportionment and the post-census certification
of seats sent to each state do not allow revisions to be made. The
Court said it found no intent to bar judicial relief if a state believes
a serious error in the census led to an incorrect apportionment.
Questions about the information contained in this News Alert may be
directed to Terri Ann Lowenthal at 202/484-2270 or, by e-mail at
<terriann2k(a)aol.com>. For copies of previous News Alerts and other
information, use our web site www.census2000.org. Please direct all
requests to receive News Alerts, and all changes in
address/phone/fax/e-mail, to the Census 2000 Initiative at
<Census2000(a)ccmc.org> or 202/326-8700. Please feel free to circulate
this information to colleagues and other interested individuals.
I am trying to calculate the median income for a region using the Pareto Interpolation method like the Census Bureau. I cannot find the correct equation. If I did find it, I did not know how to convert it into an Excel formula. Does anyone have an Excel spreadsheet that has the necessary formulas for calculating medians using the Pareto Interpolation method? Thanks, Daryl
--
Daryl Scott
South Western Regional Planning Agency
Stamford Government Center
888 Washington Blvd., 3rd Floor
Stamford, CT 06901
Tel: (203) 316-5190
Fax: (203) 316-4995
E-mail: dscott(a)swrpa.org
I don't care much for the term "Development Excellence" because it adds to
the vagueness already surrounding the term smart growth. It strikes me as
another chapter the seemingly unending search for words that will not offend
anyone because they can be easily defined anyway one wishes, and often are,
perpetuating issue confusion.
I think that planners always have to be mindful of their communities when
they plan, but there are so many similarities of development and mentality
that a book like the "Geography of Nowhere" could be written and be easily
defended.
My concept of smart growth is that of informing and educating the public.
Smart growth is about choices. Too many times, people make decisions based
on lack of information or disinformation. If people really want urban
sprawl, they need to know the consequences and trade-offs to themselves,
their children, and the environment.
Let's face it, there are a lot of people out there who are ignorant. They
are part of two somewhat overlapping circles of people; those that do not
know and those who do not WANT to know. By-and-large, though, I believe
that if people are educated about the choices and consequences, they try to
do the right thing.
Raving on,
David Kruse, AICP
-----Original Message-----
From: michael.aulick(a)ci.austin.tx.us
[mailto:michael.aulick@ci.austin.tx.us]
Sent: Monday, June 17, 2002 3:17 PM
To: korski(a)erols.com; ed.herlihy(a)comcast.net
Cc: ctpp-news(a)chrispy.net
Subject: RE: [CTPP] INNOVATION BRIEFS Advisory
Ken,
As the MPO Executive Director in the Austin Texas metropolitan area, I hear
a lot about "Smart Growth". I like the term used by the North Central Texas
COG better - "Development Excellence." I agree with the NCTCOG that quality
of life in land use and transportation is what we're after, whether that be
in low density or high density development. All metropolitan areas have
some similarities, e.g. predominance of the automobile, but they have some
differences, too, e.g. propensity for passenger rail systems in congested
corridors. I don't think national trends are helpful to planners in
individual areas trying to find solutions to problems with specific local
conditions. There is a lot of situation diversity between metropolitan
areas and within them, too. Therefore, different solutions work in
different places and under different conditions. The solutions should be
customized for each area, taking advantage of applicable lessons learned
from peer cities.
I think that opinionated positions on land use and transportation lead to a
"I'm right/ you're wrong" mentality driven by egos that only leads to a lot
of heat and not much light in solving urban problems.
Thanks for the opportunity,
Michael Aulick
> -----Original Message-----
> From: C Kenneth Orski [SMTP:korski@erols.com]
> Sent: Sunday, June 16, 2002 10:57 AM
> To: Ed Herlihy
> Cc: ctpp-news(a)chrispy.net
> Subject: Re: [CTPP] INNOVATION BRIEFS Advisory
>
> Ed -
> Perhaps my point of view will become clearer if you see the entire
> Brief, which is attached. Unlike you, most "smart growth" and
> anti-automobile crusaders refuse to accept the implications of the
> trends revealed by the 2000 census. You would understand what I mean if
> you took part (as I do) in some of the other forums devoted to "smart
> growth" and anti-automobile proselytizing, such as CNU (Congress of New
> Urbanism), STPP and TLC-net. Unfortunately, many "smart growth" and
> anti-auto zealots are not as reasonable and clear thinking as you. They
> do not let facts interfere with their ideology.
> Regards,
> Ken Orski
> ----------------
>
> Ed Herlihy wrote:
> >
> > Ken:
> >
> > As one of those who happens to support the Smart Growth movement you can
> > rest assured that I was not at all "surprised" by the new data in the
> Year
> > 2000 Census. Most of us who follow these things, even casually, knew
> full
> > well that the aggregate trends were (and are) still going in the "wrong"
> > direction. Lets remember, the Smart Growth movement is just a "babe in
> the
> > woods" and it may take decades for the message to take hold.
> >
> > Perhaps the message of Smart Growth will not take hold and perhaps there
> are
> > some land speculators who still expect to derive huge profits from
> sprawl
> > and the proliferation of large lot McMansions. So be it.
> >
> > But it is not the job of the "new Census data" to send us a message that
> all
> > of the Smart Growth ideas are a "failure". And it was never the message
> > from the Smart Growth folks that the car was going to be obsolete at any
> > time in the future.
> >
> > It is the job of planners to seek out solutions that best serve our
> > communities. And, as we dig into the census data, we will most likely
> find
> > some exceptions to the overall trends that will tell a good story about
> > Smart Growth and its benefits.
> >
> > Ed Herlihy
> > Reston, VA
> >
> > PS. OK, I fully agree the CTPP may not the best list to start a
> discussion
> > about the merits of Smart Growth. If the list moderators have a
> suggestion,
> > I will be glad to move the discussion to a more appropriate forum, if
> there
> > is one. Any suggestions? << File: New Census Data Provides Reality
> Check.doc >>
Ken,
As the MPO Executive Director in the Austin Texas metropolitan area, I hear
a lot about "Smart Growth". I like the term used by the North Central Texas
COG better - "Development Excellence." I agree with the NCTCOG that quality
of life in land use and transportation is what we're after, whether that be
in low density or high density development. All metropolitan areas have
some similarities, e.g. predominance of the automobile, but they have some
differences, too, e.g. propensity for passenger rail systems in congested
corridors. I don't think national trends are helpful to planners in
individual areas trying to find solutions to problems with specific local
conditions. There is a lot of situation diversity between metropolitan
areas and within them, too. Therefore, different solutions work in
different places and under different conditions. The solutions should be
customized for each area, taking advantage of applicable lessons learned
from peer cities.
I think that opinionated positions on land use and transportation lead to a
"I'm right/ you're wrong" mentality driven by egos that only leads to a lot
of heat and not much light in solving urban problems.
Thanks for the opportunity,
Michael Aulick
> -----Original Message-----
> From: C Kenneth Orski [SMTP:korski@erols.com]
> Sent: Sunday, June 16, 2002 10:57 AM
> To: Ed Herlihy
> Cc: ctpp-news(a)chrispy.net
> Subject: Re: [CTPP] INNOVATION BRIEFS Advisory
>
> Ed -
> Perhaps my point of view will become clearer if you see the entire
> Brief, which is attached. Unlike you, most "smart growth" and
> anti-automobile crusaders refuse to accept the implications of the
> trends revealed by the 2000 census. You would understand what I mean if
> you took part (as I do) in some of the other forums devoted to "smart
> growth" and anti-automobile proselytizing, such as CNU (Congress of New
> Urbanism), STPP and TLC-net. Unfortunately, many "smart growth" and
> anti-auto zealots are not as reasonable and clear thinking as you. They
> do not let facts interfere with their ideology.
> Regards,
> Ken Orski
> ----------------
>
> Ed Herlihy wrote:
> >
> > Ken:
> >
> > As one of those who happens to support the Smart Growth movement you can
> > rest assured that I was not at all "surprised" by the new data in the
> Year
> > 2000 Census. Most of us who follow these things, even casually, knew
> full
> > well that the aggregate trends were (and are) still going in the "wrong"
> > direction. Lets remember, the Smart Growth movement is just a "babe in
> the
> > woods" and it may take decades for the message to take hold.
> >
> > Perhaps the message of Smart Growth will not take hold and perhaps there
> are
> > some land speculators who still expect to derive huge profits from
> sprawl
> > and the proliferation of large lot McMansions. So be it.
> >
> > But it is not the job of the "new Census data" to send us a message that
> all
> > of the Smart Growth ideas are a "failure". And it was never the message
> > from the Smart Growth folks that the car was going to be obsolete at any
> > time in the future.
> >
> > It is the job of planners to seek out solutions that best serve our
> > communities. And, as we dig into the census data, we will most likely
> find
> > some exceptions to the overall trends that will tell a good story about
> > Smart Growth and its benefits.
> >
> > Ed Herlihy
> > Reston, VA
> >
> > PS. OK, I fully agree the CTPP may not the best list to start a
> discussion
> > about the merits of Smart Growth. If the list moderators have a
> suggestion,
> > I will be glad to move the discussion to a more appropriate forum, if
> there
> > is one. Any suggestions? << File: New Census Data Provides Reality
> Check.doc >>
Actually, many smart growth advocates are quite clear headed about the
role of the automobile in shaping our built environment, and those who
say otherwise are either misinformed or intentionally misrepresenting
the facts. Check out the principles and work of the Smart Growth
Network (see my .sig for link).
Citizens demanding smart growth have cars, and drive them. They also
have feet, and walk. They want choices. Some have kids, and want them
to have choices. Low-density, single-use, no-choice automobile sprawl
doesn't provide the quality of life and choices that many Americans
want, and it has demonstrably worse environmental outcomes than smart
growth. That same "LDSUNCAS" has a 50-70 year head start and is
bolstered by past demographic trends that are now changing (e.g. aging
boomers), outdated policies and standards that haven't been changed yet
(e.g., transportation funding, street design), outdated mindsets that
haven't changed yet (e.g., read the papers!), and a cadre of outmoded
professionals who desperately need to defend "business as usual" to keep
the funding spigot open. Look around -- what financial stake do many
who advocate smart growth have in its success? Then look at the
defenders of the status quo.
Smart growth is clearly not "no growth". Smart growth is clearly not
"anti-auto". Where's the "innovative" alternative to the choice-less,
unloved landscape that the old paradigm has built. For more and more
Americans, the alternative of choice is smart growth.
Time to change.
Chris.
------------------------------------
Christopher V. Forinash
U.S. EPA: Office of Policy, Economics and Innovation
1200 Pennsylvania Ave NW (MC 1808), Washington DC 20460
(Delivery: 401 M St. SW, #WT-1013D)
202-260-5044 vox 0174 fax; forinash.christopher(a)epa.gov
------------------------------------
Development, Community & Environment Division:
http://www.epa.gov/smartgrowth
A partner in the Smart Growth Network: http://www.smartgrowth.org
C Kenneth Orski
<korski(a)erols.co To: Ed Herlihy <ed.herlihy(a)comcast.net>
m> cc: ctpp-news(a)chrispy.net
Sent by: Subject: Re: [CTPP] INNOVATION BRIEFS Advisory
owner-ctpp-news@
chrispy.net
06/16/2002 11:57
AM
Ed -
Perhaps my point of view will become clearer if you see the entire
Brief, which is attached. Unlike you, most "smart growth" and
anti-automobile crusaders refuse to accept the implications of the
trends revealed by the 2000 census. You would understand what I mean if
you took part (as I do) in some of the other forums devoted to "smart
growth" and anti-automobile proselytizing, such as CNU (Congress of New
Urbanism), STPP and TLC-net. Unfortunately, many "smart growth" and
anti-auto zealots are not as reasonable and clear thinking as you. They
do not let facts interfere with their ideology.
Regards,
Ken Orski
----------------
Ed Herlihy wrote:
>
> Ken:
>
> As one of those who happens to support the Smart Growth movement you
can
> rest assured that I was not at all "surprised" by the new data in the
Year
> 2000 Census. Most of us who follow these things, even casually, knew
full
> well that the aggregate trends were (and are) still going in the
"wrong"
> direction. Lets remember, the Smart Growth movement is just a "babe
in the
> woods" and it may take decades for the message to take hold.
>
> Perhaps the message of Smart Growth will not take hold and perhaps
there are
> some land speculators who still expect to derive huge profits from
sprawl
> and the proliferation of large lot McMansions. So be it.
>
> But it is not the job of the "new Census data" to send us a message
that all
> of the Smart Growth ideas are a "failure". And it was never the
message
> from the Smart Growth folks that the car was going to be obsolete at
any
> time in the future.
>
> It is the job of planners to seek out solutions that best serve our
> communities. And, as we dig into the census data, we will most likely
find
> some exceptions to the overall trends that will tell a good story
about
> Smart Growth and its benefits.
>
> Ed Herlihy
> Reston, VA
>
> PS. OK, I fully agree the CTPP may not the best list to start a
discussion
> about the merits of Smart Growth. If the list moderators have a
suggestion,
> I will be glad to move the discussion to a more appropriate forum, if
there
> is one. Any suggestions?
(See attached file: New Census Data Provides Reality Check.doc)
Thanks for posting the article. I skipped it when I saw the subscription
fee.
I would like to point out an error in the 2000 source used for the
comparisons altho it isn't likely to refute the trends. The article
references the Census Supplementary Survey and goes on to say that it is
from the long form Census questionnaire. This in not the case as the
Supplementary Survey is not part of the Decennial Census and was taken over
a year's time from Nov. 1999 thru Dec. 2000. Among its purposes is
validating the proposed American Community Survey long term survey
procedures with the data collected from the decennial long form survey.
Unlike the 20 million households contacted in the Decennial Census long form
survey, fewer than 1 million were contacted during the Supplementary Survey.
There may also be some differences in the results in a survey taken over a
year's time compared to one describing one referenced census week in March.
Bicycle commuting comes to mind.
The actual Decennial Census long form data for Sumary File 3 is just now
coming out, so it wouldn't hurt to re-do these comparisons. Like I said,
it's probably not going to make much of a change in the findings, but for
analytical purposes I still like to know I'm working with apples and apples.
Don Burrell, Senior Planner
Bicycle / Pedestrian Coordinator
OKI Regional Council of Governments
801-B West Eighth St. Suite 400
Cincinnati, OH 45203-1607
513-621-6300
513-621-9325 - fax
dburrell(a)oki.org <mailto:dburrell@oki.org>
<A bicycle is an instrument for playing the road>
-----Original Message-----
From: C Kenneth Orski [mailto:korski@erols.com]
Sent: Sunday, June 16, 2002 11:57 AM
To: Ed Herlihy
Cc: ctpp-news(a)chrispy.net
Subject: Re: [CTPP] INNOVATION BRIEFS Advisory
Ed -
Perhaps my point of view will become clearer if you see the entire
Brief, which is attached. Unlike you, most "smart growth" and
anti-automobile crusaders refuse to accept the implications of the
trends revealed by the 2000 census. You would understand what I mean if
you took part (as I do) in some of the other forums devoted to "smart
growth" and anti-automobile proselytizing, such as CNU (Congress of New
Urbanism), STPP and TLC-net. Unfortunately, many "smart growth" and
anti-auto zealots are not as reasonable and clear thinking as you. They
do not let facts interfere with their ideology.
Regards,
Ken Orski
----------------
Ed Herlihy wrote:
>
> Ken:
>
> As one of those who happens to support the Smart Growth movement you can
> rest assured that I was not at all "surprised" by the new data in the Year
> 2000 Census. Most of us who follow these things, even casually, knew full
> well that the aggregate trends were (and are) still going in the "wrong"
> direction. Lets remember, the Smart Growth movement is just a "babe in
the
> woods" and it may take decades for the message to take hold.
>
> Perhaps the message of Smart Growth will not take hold and perhaps there
are
> some land speculators who still expect to derive huge profits from sprawl
> and the proliferation of large lot McMansions. So be it.
>
> But it is not the job of the "new Census data" to send us a message that
all
> of the Smart Growth ideas are a "failure". And it was never the message
> from the Smart Growth folks that the car was going to be obsolete at any
> time in the future.
>
> It is the job of planners to seek out solutions that best serve our
> communities. And, as we dig into the census data, we will most likely
find
> some exceptions to the overall trends that will tell a good story about
> Smart Growth and its benefits.
>
> Ed Herlihy
> Reston, VA
>
> PS. OK, I fully agree the CTPP may not the best list to start a discussion
> about the merits of Smart Growth. If the list moderators have a
suggestion,
> I will be glad to move the discussion to a more appropriate forum, if
there
> is one. Any suggestions?
INNOVATION BRIEFS Advisory
July/August 2002
==========================================
Abstracts of the latest issue of Innovation Briefs are now
available on our website at:
http://www.innobriefs.com/abstracts/2002/july02.html
+ New Census Data Provides a Reality Check
+ Relieving Highway Congestion
+ The Myth of the Underfunded Mass Transit
+ Financing Future Transportation Needs
Part I: Short-Term Revenue Enhancements
+ Toward a Hydrogen-Based Future
+ "HOT Networks"
For a full version, subscribe to Innovation Briefs
at an introductory annual rate of $50.
Note to our congressional and federal government subscribers:
If you are experiencing serious delays in receiving
"snail mail," you may request e-mail delivery of
Innovation Briefs by contacting us at korski(a)erols.com
-------------------------------------------------------------------
INNOVATION BRIEFS
10200 Riverwood Drive, Potomac, MD 20854-1536
Tel: 301.299.1996; Fax: 301.299.4425
Email: korski(a)erols.com
#################################################################
#################################################################
#################################################################
#####
#####
#####
#################################################################
#################################################################
#################################################################
1990 Census Tract Outline Maps
The Census Bureau as recreated the 1990 Census Tract Outline maps and has made them available on the web.
You may access the 1990 Census Tract Outline maps directly from the ftp site at:
http://ftp2.census.gov/geo/maps/trt1990/
Once we have updated the Map Products page (next week), they will be available from that page:
http://www.census.gov/geo/www/maps/CP_MapProducts.htm
It is important to note that these PDF maps are re-creations of the 1990 Census Tract/BNA outline maps and differ from the original 1990 Census Tract Outline Maps. Similar to the 2000 Census Tract outline maps, these maps are county-based and created for all 1990 Counties/County Equivalents in the United States. All maps utilize 1990 geography; however, display features are based on what was used for Census 2000. These maps show the boundaries and numbers of the 1990 census tracts/BNAs as well as the named features underlying the boundaries. They also show the boundaries, names and codes for 1990 American Indian/Alaska Native areas, counties, county subdivisions, and places. The scale of the maps will be optimized to keep the number of map sheets for each area to a minimum, but the scale and number of sheets will vary by the area size of the county and the complexity of the census tracts.
File naming convention:
State - stSS_statename (e.g. st12_Florida/);
County - SSCCC_countyname (e.g. 12099_PalmBeach/ st12_Florida/);
Sheet number/File - 90TSSCCC_(sheet number).pdf (e.g. 90T12009_001.pdf).
2002 TIGER/Line Files
I am attaching a PDF with the 2002 TIGER/Line format. As previously mentioned, there are major structural changes in this layout. We have eliminated some record types (3 and 9) and added others (B,E,T,U). We have rearranged the location of the data fields. We have added a large number of reserved fields on some of the record types to account for fields we expect to use in 2003 or later -- fields that will accommodate, for example, the new MA delineations expected from OMB next year based on their new core-based statistical areas. Fields are also set aside to accommodate information we expect to have in files that have been processed through the MAF/TIGER Accuracy Improvement Program.
Also, please note that we have added a permanent zero-cell identification number to each node (TZID). The TZID is similar in concept to the TLID and appears on RT I and the new RT T. The possible range for the TZID, with the highest value used for that range, appears in RT R.
One of the major difficulties data users had last decade was the mixing of "current" state and county codes with the census tract and block numbers which are uniquely identified only by the census state and county codes. For this reason, RT 1 continues to provide Census 2000 codes even though the distribution unit will be current county. Thus, it is possible that to fully match all the Census 2000 block numbers in a Census 2000 county a user will need to reference multiple "current" 2002 TIGER/Line files. An example of this will be Broomfield County, CO which was created last year (after Census 2000) from parts of four other Colorado counties.
We expect that the 2002 TIGER/Line files will contain a small number of counties with improved road coordinates based upon work that we have been doing in the past year. Tentatively, we expect these counties to be included (list is subject to change):
10001 Kent, DE
10003 New Castle, DE
10005 Sussex, DE
12117 Seminole, FL
24015 Cecil, MD
24039 Somerset, MD
24041 Talbot, MD
24510 Baltimore City, MD
39011 Auglaize, OH
39033 Crawford, OH
39039 Defiance, OH
39041 Delaware, OH
39051 Fulton, OH
39069 Henry, OH
39109 Miami, OH
39137 Putnam, OH
39139 Richland, OH
39161 Van Wert, OH
39171 Williams, OH
46065 Hughes, SD
If you have any questions, please let me know. We are working on the full documentation, but it will not be ready until the end of the summer. We expect the 2002 TIGER/Line files to be available the last calendar quarter of this year.
Bob LaMacchia
Geography Division
rlamacchia(a)geo.census.govGeography Division
