Female LPM Regression Analysis

Presented in Table 30 are the variable descriptive statistics for the 94,679 female observations in the sample. The data show an overall attrition rate for women of 28.81 percent. Most women fall within the AFQT category IIIB at 33.55 percent, followed by category II at 31.98 percent. The most populous age category is the 18-20 year olds, which make up 51.07 percent of the sample, followed by those less-than-18 years of age at 27.05 percent.

Table 30. Summary of LPM Variables for Women

Name Variable Description Obs Mean Std. Dev. Min Max

Did not pass state exit

exam = 1 if true, 0 false 94679 0.3637 0.4811 0 1

Name Variable Description Obs Mean Std. Dev. Min Max asian_pi Asian/Pacific Islander = 1 if true, 0 false 94679 0.0394 0.1945 0 1 black Black = 1 if true, 0 false 94679 0.2236 0.4167 0 1 Source: Derived from data provided by Defense Manpower Data Center (DMDC), 2009.

Table 31 presents the female LPM regression results for all Tiers combined and individual education credentials grouped into respective Tiers. The R-squared value is 0.1013 and the probability of attrition for the base individual is 0.3236. The data show

that the probability of attrition decreases by 0.0328 for women in AFQT category I and decreases by 0.0148 for women in AFQT category II. The probability attrition for woman in AFQT category IIIB decreases by 0.0054. Category I and II variables are both statistically significant at the 1 percent level, while the category IIIB variable is significant at the 15 percent level. Only the less-than-18 age variable is significant at the 1 percent level. The over-30 age variable is significant at the 10 percent level. The other age variables are not significant. The under-18 variable decreases the probability of attrition by 0.0483, while the over-30 age variable decreases probability of attrition by 0.0174. The data show that the probability of attrition for Tier II woman increases by 0.0349 and the probability of attrition for Tier III woman increases by 0.0273. Both Tier II and Tier III variables are statistically significant at the 10 percent level.

Table 31. Binary LPM, Tiers, Regression Results for Women

Variable Coefficient Robust Std. Error p-Value

I -0.0328 0.0082 0.0000

Variable Coefficient Robust Std. Error p-Value

Source: Derived from data provided by Defense Manpower Data Center (DMDC), 2009.

Base individual is a Tier I white female with category IIIA AFQT who entered DEP in 1999.

Table 32 presents the female LPM regression results for all Tiers broken down by each education credential. The R-squared value is 0.1024 and the probability of attrition for the base individual is 0.3169. The data show that the probability of attrition decreases by 0.0321 for women in AFQT category I and decreases by 0.0142 for those in AFQT category II. The probability attrition for women in category IIIB decreases by 0.0054.

Category I and II variables are both statistically significant at the 1 percent level, while category IIIB is significant at the 15 percent level. Only the less-than-18 age variable is significant at the 1 percent level. The over-30 age variable is significant at the 10 percent level. The other age variables are not significant. The less-than-18 variable decreases probability of attrition by 0.0556 while the over-30 age variable decreases the probability of attrition by 0.0200. The data show that the probability of attrition for women with a GED increases by 0.0503 and the probability of attrition for those with no education credential increases by 0.0338. Education variables I_hss, I_cnc, I_ba, II_ged, and III_hsd are all statistically significant at the 10 percent level.

Table 32. Binary LPM, Education Codes, Regression Results for Women

Variable Coefficient Robust Std. Error p-Value

I -0.0321 0.0082 0.0000

Variable Coefficient Robust Std. Error p-Value

Source: Derived from data provided by Defense Manpower Data Center (DMDC), 2009.

Base individual is a high school diploma graduate white female with category IIIA AFQT who entered DEP in 1999.

Figures 36 through 38 show similar calculations as done for men (seen in Figures 33 through 35). The data show that for woman the probability of attrition increases with age between the than-18 group and the over-30 group. With groups other than less-than-18 and over-30, the difference in probability of attrition increases as age decreases.

This may be due to those age groups not being statistically significant in the regression.

The data also show that the probability of attrition for woman increases as AFQT

category increases between IIIB and IIIA. The probability of attrition then decreases at a steady rate between AFQT categories IIIA and I. As with the men, the probability curves were calculated from the LPM, so there is no variation in the slopes between the different age groups and Tier classifications as shown in Figures 36 through 38. The same difference in probability caused by age is shown in all figures with the additional increase in probabilities caused by the Tier group of the individual.

II I IIIB IIIA

0.22 0.24 0.26 0.28 0.30 0.32

AFQT Category

Probability of Attrition 21_23

18_20 24_26 27_29

>30

<18

Source: Derived from data provided by Defense Manpower Data Center (DMDC), 2009.

Figure 36. Tier I LPM of Attrition by Age and AFQT Category for Women

II I

Source: Derived from data provided by Defense Manpower Data Center (DMDC), 2009.

Figure 37. Tier II LPM of Attrition by Age and AFQT Category for Women

I

Source: Derived from data provided by Defense Manpower Data Center (DMDC), 2009.

Figure 38. Tier III LPM of Attrition by Age and AFQT Category for Women