Documentation: Census 1970
you are here: choose a survey survey document chapter
Publisher: U.S. Census Bureau
Survey: Census 1970
Document: 1970 Census Users' Guide - Part II
citation:
Social Explorer; U.S. Census Bureau; 1970 Census Users’ Guide; U. S. Government Printing Office, Washington, D. C., 1970.
Chapter Contents
1970 Census Users' Guide - Part II
Fourth Count Population Summary Tape
Subject: Description, Content, and Arrangement of the 1970 Census of Population and Housing Fourth-Count Population Tallies

File Titles:
File A: Fourth-Count Tallies: Population Counts in Complete Tracts.
File B: Fourth-Count Tallies: Population Counts in Minor Civil Divisions or Census County Divisions.
File C: Fourth-Count Tallies: Population Counts in Selected Census Areas--(see Summary Categories and Sequencing
Keys for Files B and C).

The Fourth Count Population Summary Tapes are created from the sample files used to prepare tables for Census of Population , Volume I, Chapter C and the "Census Tract Reports." The tapes contain more data items for tracts and other small areas reported than are found in printed reports.

The Fourth Count Population Summary Tape series is part of the first of three series of computer tapes presenting sample data. Tapes in the Fourth Count series will be released on a State-by-State basis as the data are processed. It is estimated that File A, which presents data for tracts, will include 162 tape reels for all States; File B, which presents data for Minor Civil Divisions or Census County Divisions, will include 176 tape reels for all States; and File C, which presents data for selected census areas, will include 104 tape reels for all States.
The Fourth Count data files are considered final at the time they are created-- they will not be updated as a result of subsequent tabulations of this or later censuses. The master tapes, from which copies are prepared, are held in permanent storage. The data items have been reviewed for disclosure and suppressed as necessary; therefore, no data are released which would violate the confidentiality of information on individuals.

1.Technical conditions affecting the use of Fourth-Count Summary Tapes.
a. Reel Size: 10 1/2 inch diameter, maximum 2400 feet.
b. Recording density (CPI): 556 or 800 on 7-channel; 800 on 9-channel.
c. Record/Field Size: Fixed length 2,040 character physical record size; 8 or 16 character field size.

Both Files A and B can consist of 5 logical records (consisting of up to 22 physical records) for each tract or MCD (CCD).The logical records are:

File A Logical Records Maximum number of Physical Records
Record Type1    1 5
"        "               2 5
"        "               3 5
"        "               4 5
"        "               5 2


File B Logical Records Maximum number of Physical Records
Record Type1    01 5
"        "               02 5
"        "               03 5
"        "               04 5
"        "               13 2


File C can consist of 14 logical records (consisting of up to 64 physical records) for each geographic area summarized. They are:
Record types 01 to 12 - 5 physical records each
Record types 13 and 14 - 2 physical records each

d. Parity: Even for 7-channel, odd for 9-channel.
e. Language: Binary Coded Decimal (BCD) on 7-channel; Extended Binary Coded Decimal Interchange Code (EBCDIC) and the American Standard Code for Information Interchange (ASCII) on 9-channel. A limited set of characters is used.
f. Record Spacing: 3/4 inch inter-record spacing on 7-channel; .6 on 9-channel.
2.File Size . (There will be one or more tapes for each file for every State.)

File A: Approximately 140,000 logical records representing about 35,000 tracts for the United States.
File B: Approximately 152,000 logical records representing about 37,500 MCDs (CCDs) for the United States.
File C: Approximately 100,000 logical records representing about 13,000 summary areas for the United States.
3.File Format .
a. Labels: Header and trailer labels-- (See Technical Conventions for 1970 Census Summary Tapes, 1970 Census Users Guide.)

Footnote:
1The term record type is used when referring to a specific logical record. See section 3.b for a discussion of the arrangement of record file.

File A, File Identifier:
STYYX4CPbbbbbbbbb where YY = 1960 State Code
Set Identifier: CT4A70

File B, File Identifier:
STYYX4CPbbbbbbbbb where YY = 1960 State Code
Set Identifier: CT4B70

File C, File Identifier:
STYYX4CPbbbbbbbbb where YY = 1960 State Code
Set Identifier: CT4C70

Tape label fields are described so that a user can specify on his system control cards exactly what contents a tape label should have, but some users may wish to use an option to not specify label contents and thereby accept whatever tape reel gets mounted on the tape drive.

b. Sequence of Files:

File A: This file is composed of complete tract summaries. There are up to 5 logical records for each tract. Record type 1 is Total Population. Record type 2 is White Population. Record type 3 is Negro Population. Record type 4 is Spanish-American Population. Record type 5 is Allocations. The file is in sort (ascending sequence ) by 1970 county of tabulation code, tract number (including suffix), and record type.

Record types 1 through 4 are data records, each consisting of 120 characters of geographic identification, followed by 60 sixteen-character aggregate tally fields and 1,118 eight-character population tally fields. Each record type contains tabulations 1-99.

Record type 5 is the allocation record consisting of 120 characters of geographic identification followed by 252 eight-character tallies, 10 sixteen-character tallies, and 4 eight-character tallies. These tallies comprise tabulations 100-127 (see pp. 60-68).

File B: The file is composed of summaries for minor civil divisions (MCDs) or census county divisions (CCDs). There are up to 5 logical records for each MCD or
CCD. The file is in sort by 1970 county of tabulation code, MCD or CCD code, and record type.

Record types 01 through 04 are data records, each consisting of 120 characters of geographic identification, followed by 60 sixteen-character aggregate tally fields and 1,118 eight-character population tally fields. Each record type contains tabulations 1 - 99.

Record type 13 is the allocation record consisting of 120 characters of geographic identification followed by 252 eight-character tallies, 10 sixteen character tallies, and 4 eight-character tallies. These tallies comprise tabulations 100 - 127.

File C: This file is composed of selected census summary areas. It is in sort by the sequencing keys in characters 103 - 119. The file contains up to 20 summary categories, each containing one or more geographic summary units. There are up to 14 logical records for each summary unit. The first summary category is the State. This is followed by 9 State level component summaries. These are followed by the appropriate number of Standard Consolidated Area (SCA) and individual standard metropolitan statistical area (SMSA) summaries. Three types of SMSA component summaries follow each SMSA summary. A summary for each urbanized area (UA) in the State follows the SMSAs and two types of UA components follow each UA. Place summaries are next, one for each place of 2,500 population or more, including New England towns. Finally, the file contains a summary for each county in the State. Summaries for SCAs, SMSAs and UAs which cross State lines will consist of those portions within the designated State.

Record types 01 through 12 are data records, each consisting of 120 characters of geographic identification, followed by 60 sixteen-character aggregate tally fields and 1,118 eight-character population tally fields. Each record type contains tabulations 1 - 99.

Record types 13 and 14 are the allocation records, each consisting of 120 characters of geographic identification followed by 252 eight-character tallies, 10 sixteen-character tallies, and 4 eight character tallies. These tallies comprise tabulations 100-127.

c. Data:
The FORTRAN format statement of the data record is:

A1,A2,3X,A2,3X,A1,2X,A3,1X,A4,2X,A4,A2,6X,A1,11X,A1,A4,1X,A4,A2,A4,2A1,2X3,A2,A4,18X,A2,A1,3X,2A2,13A1,A1,7I16,8X,7I16,8X,7I16,8X,7I16,8X,7I16,8X,7I16,8X,7I16,8X,7I16,8X,4I16,112I8/255I8/255I8/255I8/241I8,112X

The FORTRAN format statement of the allocation record is:

A1,A2,3X,A2,3X,A1,2X,A3,1X,A4,2X,A4,A2,6X,A1,11X,A1,A4,1X,A4,A2,A4,2A1,2A3,A2,A4,18X,A2,A1,3X,2A2,13A1,A1,240I8/12I8,I16,8X,7I16,8X,21I6,4I8,1736X
where:

rAw - Alphanumeric field
rIw - Numeric data field
wX - Padding (space) field
,- Field separator
/- Physical record separator
r - Repeat count for field (no entry for r means 1 is assumed)
w - Field length

4.Reference .
See Census Users Dictionary of the 1970 Census Users Guide for definitions of subject concepts and geographic area terms.

5.Tabulation Description Elements .
Each tabulation in the file is described in terms of its major components or elements. The first element (A) is the tabulation number. The second element (B) is the tabulation title. The tabulation title is a unique description of each tabulation on the tape. The order of presentation of items on the tape is not reflected in the title. The third element (C) is the number of data items. The fourth element (D) is the universe being tabulated; e.g., persons, persons 14 years and over, vacant housing units. The fifth element (E) constitutes the variables or stratifiers by which the universe is classified; e.g., age, sex, plumbing facilities. The name of each stratifier is preceded by the word By and followed in parentheses by the number of categories of the particular stratifier. Below the stratifier names is listed the sixth element, stratifier categories (F), used to classify the universe in the particular tabulation. An example follows:

21. (A) POPULATION 14 YEARS OLD AND OVER BY MARITAL STATUS, RACE, AND SEX (B) 20
Count of Persons 14 Years Old and Over (D)
By: Race (2) (E) By: Sex (2) (E) By: Marital Status (5) (E)
Total :(F)
Male: (F)
Now Married(excludes separated) (F)
Widowed (F)
Divorced (F)
Seperated (F)
Never Married (F)
Female: (F)
Repeat Marital Status (5) (F)
Negro: (F)
Same as Total (10) (F)
Key:
A -Tabulation number
B- Tabulation title
C- Total number of data items in tabulation
D- Universe
E- Stratifier names and number of categories
F- Stratifier categories


Note the use of the colon following some of the stratifier categories. This indicates that there is no actual item of data on the tape for that category as such. Looking back at the example, the first item or number on the tape for tabulation 21 is for Total males now married, the second item for Total males widowed. Following five items of Marital status for males, the 6th item is Total females now married, the 11th item is Negro males now married, and so on.

6.Position Identification.
At the top of each page describing the data within this file is a unit identifier. It is used to pinpoint the physical location on the tape file of the first character in the first data field described on that page. The elements describing the position are the number of the Block (physical record), number of the Subblock (a logical division of the Block into sets of 120 characters each) , and initial character within Subblock.

7.Suppression Indicator.
The data records have a suppression indicator of SO for all the tabulations within the record. The allocation records have a suppression indicator of SX for all the tabulations within the record. Type of suppression and example are shown in Technical Conventions for 1970 Census Summary Tapes, 1970 Census Users Guide.

8.Accuracy of the Data.
See 1970 Census Users Guide for information on sources of error, editing of unacceptable data, ratio estimation, and sampling variability.

Categories (File C: 1 - 20; File B: 21)

1. State
STATE LEVEL COMPONENTS

2. Total Urbanized Areas in State
3. Central Cities of UAs (Urban Portion)
4. Urban Fringe of UAs
5. Urban Places with 10,000 or more population outside UAs
6. Urban Places with 2,500-10,000 population outside UAs
7. Total Standard Metropolitan Statistical Areas in State
8. Central cities of SMSAs (Urban Portion)
9. Other Territory of SMSAs
10. Non-SMSA Territory in the State

SCA's, SMSAs, AND SMSA COMPONENTS

11. Standard Consolidated Area
12. SMSA
13. Each County in the SMSA
14. Each Central City or city with 50,000 or more population inside the SMSA (Urban Portion)
15. Balance of each SMSA

OTHER COMPONENTS
16. Each Urbanized Area
17. Each Central City of the UA (Urban Portion)
18. Urban Fringe of the UA
19. Place with 2,500 or more population, including New England Towns
20. County
21. MCD (File B Only)

ST = Report State Code (1960)
R= SCA Code
SMSA = SMSA Code
URBA = UA Code
COU = County Code (Publication - 1970)
PLAC = Place Code
MCD = MCD or CCD Code
XX= True State Code (1970). Used when summary area extends into another State for summary types 26, 30, and 40.
SZ = Place Size and Town Size

YY = Record Type: (File C)

01= Urban- Total Population
02= Urban- White Population
03= Urban- Negro Population
04= Urban- Spanish American Population
05= Rural Nonfarm - Total Population
06= Rural Nonfarm - White Population
07= Rural Nonfarm - Negro Population
08= Rural Nonfarm - Spanish-American Population
09= Rural Farm - Total Population
10= Rural Farm - White Population
11= Rural Farm - Negro Population
12= Rural Farm - Spanish-American Population
13= Urban Allocations*
14= Rural Allocations*

ZZ = Record Type: (File B)

01 = Total Population
02 = White Population
03 = Negro Population
04 = Spanish-American Population
13= Allocations*

The following File C summary categories will only contain up to 5 logical records ranging from 01 through 04 and allocation record type 13: 2, 3, 4, 5, 6, 8, 14, 16, 17, 18, and 19. All other File C categories may contain the full array of record types from 01 through 12 and allocation record types 13 and 14.

GEOGRAPHIC IDENTIFICATION (For definitions of items see Census Users Dictionary) GEOGRAPHICAL UNIT SUMMARIZED (The symbols in the column indicate the geographical items which are applicable for each area summarized.)
Item Block 1, Subblock 1 Character File C File 1 File A
State SCA SMSA UA Place1 County2 MCD (CCD) Tract
Record Type 1               N
1970 State 2-3 N N N N N N N N
Padding 4-6                
1960 State 7-8 N N N N N N N N
Padding 9-11                
Central County Code 12           N N N
Padding 13-14                
Minor Civil Division or Census County Division 15-17             N  
Padding 18                
Place 19-22         N/b      
Padding 23-24                
Tract (Basic) 25-28               N
Tract (Suffix) 29-30               N/b
Padding 31-36                
Central Business District 37               N
Padding 38-48                
Standard Consolidated Area 49   A A/b     3A/b A/b A/b
Standard Metropolitan Statistical Area 50-53     N     3N/b N/b N/b
Padding 54                
Urbanized Area 55-58       N        
State Economic Area 59-60           A/N A/N A/N
Tracted Area 61-64     N/b         N
Place Description 65         N/b      
Specified City with Rural Territory (Overbounded/ Extended) 66         A/b      
Economic Sub-Region 67-69           N N N
1970 County of Tabulation 70-72           N N N
New England Town Size Code 73-74         N/b   N/b  
New England Town Code 75-78         N/b   N/b  
Padding 79-96                
Place Size 97-98         N/b      
Publication Code 99         N/b   N/b  
Padding 100-102                
Sequencing Keys4 or Padding 103-119                
$ Symbol 120 A A A A A A A A
N = Nonsuppressed Numeric Code. N/b = Nonsuppressed Numeric Code or b if not applicable. A/b= Alphabetic Code or b if not applicable. A/N = Alphabetic/Numeric Code. Blank = b.


Footnotes:
1Place summaries include towns in New England. Town summaries will possess the following characteristics: Place code, place description code, overbounded indicator and place size code all will be blank. New England town size code, New England town code, and publication code all will be filled. The reverse will be the case with true place summaries. Metropolitan place summaries consist of central cities or places which contain a population of 50,000 or more and are included among the SMSA component summaries. Only the urban portions of these places are included. The geographic identification will be the same as that assigned to SMSA summaries except for the sequencing keys. New England towns are never designated as metropolitan place summaries.
2Metropolitan counties are included among the SMSA components. Except for New England, they will contain the same level of data as the regular county summaries. However, in the latter category, each metropolitan and nonmetropolitan county is shown separated into urban and rural parts. In New England they contain only those data which come from inside the designated SMSA. The regular county summaries continue to carry the same level of data as non-New England counties. The geographic identification of metropolitan county summaries will be the same as that assigned to SMSA summaries-- except for the sequencing keys.
3Not applicable in New England.
4Characters 103-118 will contain various geographic codes as determined by the designated summary level for Files B and C.