Draft1970: USA 1970 Draft Lottery Data
In vcdExtra: 'vcd' Extensions and Additions

Description Usage Format Details Source References See Also Examples

This data set gives the results of the 1970 US draft lottery, in the form of a data frame.

1	data(Draft1970)

A data frame with 366 observations on the following 3 variables.

Day: day of the year, 1:366
Rank: draft priority rank of people born on that day
Month: an ordered factor with levels Jan < Feb ... < Dec

The draft lottery was used to determine the order in which elligible men would be called to the Selective Service draft. The days of the year (including February 29) were represented by the numbers 1 through 366 written on slips of paper. The slips were placed in separate plastic capsules that were mixed in a shoebox and then dumped into a deep glass jar. Capsules were drawn from the jar one at a time.

The first number drawn was 258 (September 14), so all registrants with that birthday were assigned lottery number Rank 1. The second number drawn corresponded to April 24, and so forth. All men of draft age (born 1944 to 1950) who shared a birthdate would be called to serve at once. The first 195 birthdates drawn were later called to serve in the order they were drawn; the last of these was September 24.

Starr, N. (1997). Nonrandom Risk: The 1970 Draft Lottery, Journal of Statistics Education, v.5, n.2 http://www.amstat.org/publications/jse/v5n2/datasets.starr.html

Fienberg, S. E. (1971), "Randomization and Social Affairs: The 1970 Draft Lottery," Science, 171, 255-261.

http://en.wikipedia.org/wiki/Draft_lottery_(1969)

Draft1970table

data(Draft1970)
# scatterplot
plot(Rank ~ Day, data=Draft1970)
with(Draft1970, lines(lowess(Day, Rank), col="red", lwd=2))
abline(lm(Rank ~ Day, data=Draft1970), col="blue")
 
# boxplots
plot(Rank ~ Month, data=Draft1970, col="bisque")

lm(Rank ~ Month, data=Draft1970)
anova(lm(Rank ~ Month, data=Draft1970))

# make the table version
Draft1970$Risk <- cut(Draft1970$Rank, breaks=3, labels=c("High", "Med", "Low"))
with(Draft1970, table(Month, Risk))

Loading required package: vcd
Loading required package: grid
Loading required package: gnm

Call:
lm(formula = Rank ~ Month, data = Draft1970)

Coefficients:
(Intercept)      Month.L      Month.Q      Month.C      Month^4      Month^5  
    183.528      -84.330      -31.503        5.020      -20.904      -14.052  
    Month^6      Month^7      Month^8      Month^9     Month^10     Month^11  
      2.122        3.488       21.150        1.747       15.582        1.126  

Analysis of Variance Table

Response: Rank
           Df  Sum Sq Mean Sq F value  Pr(>F)   
Month      11  290507   26410  2.4634 0.00558 **
Residuals 354 3795120   10721                   
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
     Risk
Month High Med Low
  Jan    9  12  10
  Feb    7  12  10
  Mar    5  10  16
  Apr    8   8  14
  May    9   7  15
  Jun   11   7  12
  Jul   12   7  12
  Aug   13   7  11
  Sep   10  15   5
  Oct    9  15   7
  Nov   12  12   6
  Dec   17  10   4