US Fertility Source Data
Age-order-specific birth rates, by single years of age, 14-49, for 1917-1991.
- 1st Birth Rates aosbr1.txt
- 2nd Birth Rates aosbr2.txt
- 3rd Birth Rates aosbr3.txt
- 4th Birth Rates aosbr4.txt
- 5th Birth Rates aosbr5.txt
- 6th Birth Rates aosbr6.txt
- 7th Birth Rates aosbr7.txt
- 8th and Higher Order Birth Rates aosbr8.txt
- Age-Specific Birth Rates asbr.txt
First birth rates for 1917-1973 are taken from Table 4A, pages 40-42, of the Heuser book. The published table is organized by birth cohorts. The rates for the cohort born in 1903 are shown on the line on page 40 that reads
1903------- | 1917 | 3.5 | 10.9 | ...,
1917 being the year in which the cohort born in 1903 reached age 14. Preceding rows of the table refer to earlier cohorts, for which rates for younger ages are missing because the source data series begins in 1917.
Note that birth cohort of 1903 refers here not to births in calendar year 1903, but to births during the one year period centered on the beginning of 1903, i.e., from July 1902 to June 1903. These women reach exact age 14 during the one year period centered on the beginning of 1917, i.e., they reach exact age 14 at the beginning of 1917 on the average. Similar comments apply to birth cohorts for all years.
The age-specific first birth rates for 1917 appear on the diagonal running up and to the left, i.e., 3.5 for age 14, 10.9 for age 15, 24.2 for age 16, and so on. These are the rates that appear in the first row of the table aosbr1.txt. Similar comments apply to rates for higher order births. Second birth rates are given in Table 4A on pages 43-45, third birth rates on pages 46-48, and so on.
Opening these text files in Excel or most other spreadsheet programs will initiate a procedure for converting them to the appropriate spreadsheet format. Text files have the advantage of small size and near universal readability. Calculations for the paper were done in Excel (www.microsoft.com) by Bongaarts and in Splus (www.mathsoft.com) by Feeney.
The data were entered in a large Excel spreadsheet by Bonaarts. The text files were created from the Excel file by Feeney by selecting the rates for each birth order, pasting to a temporary spreadsheet file, saving this file in .prn format, and editing the result with a text editor (TextPad). When saving to .prn format Excel silently wraps text blocks so as not to exceed 120 characters. It is necessary to use block (column) editing to undo the results of this formating.
In S-Plus, use read.table() to import the text files as data frames and data.matrix() to convert the data frames to matrices. Before doing so, however, replace the entry in the upper left had corner of the file (e.g., AOSBR1 in the file source/aosbr1.txt) with blanks to prevent read.table() from reading the year labels as variable values.
Derived Tables