Descriptive Statistics

Table 7 provides a summary of the prior service SMCR unit dataset used to estimate the parameters for Models 1 and 2. Tables 8 and 9 provide a summary of the prior RC and AC datasets used to estimate Models 3 and 4, respectively.

As Table 7 shows, the average 12-month continuation rate for this period is 55.5 percent. As shown in Appendices 27–31, the average rate ranges from 50.0 to 59.1 during the 4-, 12-, and 24-month tour lengths used in this analysis. The continuation rate also varies significantly between the prior RC and prior AC populations. According to Tables 8 and 9, the average continuation rate for prior RC is 63.8 percent, while the prior AC rate is lower at 51.9 percent. Rates for the prior RC and AC populations at the 4-, 12- and 24-month tour lengths are shown in Appendices 32–41. As discussed previously, these disparities are expected given the differences in experience and realism of job previews between the AC and RC components.

The average number of months activated for the SMCR unit population is 4.7 months; this increases to 10.75 months when only considering the 37.7 percent of prior service who have activated once, and six percent for those who have activated more frequently. As shown in Appendix 28, only 15.4 percent of all prior service new joins have previously activated. Within 24 months, the activation rate increases to 58.3 percent. As can be expected, prior service RC Marines have a 26 percentage point higher average activation rate (as shown in Tables 8 and 9).

Table 7 shows that less than two percent of all prior service SMCR unit Marines received a monetary incentive, of which only six were prior RC.¹²¹ There are two primary reasons why this number is so low. First, prior to FY2008, the maximum bonus amount ranged from $833 to $2,500 per year for a three year commitment, as shown previously in Table 5. Not until FY2008 was the bonus increased to $15,000, which was payable in a lump sum. As such, prior to FY2008 the vast majority of Marines were not willing to accept a commitment to serve in the SMCR units for the amount of money

121 The actual number may be slightly higher due to incomplete FY06 and FY07 data.

being offered. Second, RA has a limited budget to provide bonuses, although this was not a major contributing factor prior to FY2008. Bonuses are given out on a first come, first served basis.

Another difference between the prior AC and RC populations is in AFQT scores.

Tables 8 and 9 show on average, prior RC Marines scored nearly nine points higher than prior AC. Unfortunately, as indicated by the 28,761 fewer data points, approximately 12 percent of observations were missing this data element. Additionally, a relatively small number of impossibly low values also account for some of these missing data points.

Differences in descriptive statistics for the person-job fit variables between prior RC and AC Marines are unremarkable. For instance, the average duty proficiency and average conduct score of 4.5 is nearly identical for the two populations. Similarly, both population groups scored nearly the same on the 300-point PFT and 50-point BST.¹²²

On the basis of military experience, the two prior service groups differ in both rank and MOS. Although both have the same percentage of corporals (29 percent), the prior RC is more lance corporal heavy (20 percent) and the prior AC has a higher percentage of sergeants (65 percent). In addition, prior RC are approximately 11 percentage points more likely to serve in combat arms and 50 percent less likely to serve in the aviation community.

Demographically, the prior AC population is more diverse than the prior RC population with nearly twice as many females and more married service members.

Additionally, prior AC service members are more likely to be non-white and to have children.

Although the prior RC composes only 26.5 percent of the total SMCR unit observations, the differences mentioned above, particularly in the areas of activation, experience, and continuation rates, suggest important and systematic differences between the two populations. Thus, I will estimate the parameters shown in Figures 11 and 12 for prior RC and AC service members together in Models 1 and 2 and for Figure 12 separately in Models 3 and 4.

122 Scores were converted from the 5.0- to the 300-point scale using Appendix 10.

Table 7. Descriptive Statistics, All Prior Service SMCR, E3–E5 (All Observations) unemployment 222680 5.4270 1.0280 2.2 11.4

afqt 205242 60.8900 18.7200 30 99

unexcuse_12_mo 234003 0.7318 3.5730 0 48 true_reserve 212891 0.2650 0.4413 0 1 SMCR_break_PS_gt1 234003 0.1445 0.3516 0 1

satyrs 209089 6.1690 1.8620 3 14 cpl 234003 0.2859 0.4518 0 1 sgt 234003 0.6300 0.4828 0 1 combat_arms 234003 0.3357 0.4722 0 1

aviation_community 234003 0.0839 0.2773 0 1

mfr 234003 0.0535 0.2250 0 1 pacificislander 234003 0.0030 0.0545 0 1

asian 234003 0.0246 0.1550 0 1

Table 8. Descriptive Statistics, Prior RC Service SMCR, E3–E5 (All Observations) SMCR_break_PS_gt1 56418 0.1336 0.3403 0 1

satyrs 49438 6.2760 2.0990 3 14 cpl 56418 0.2925 0.4549 0 1 sgt 56418 0.5091 0.4999 0 1 combat_arms 56418 0.4125 0.4923 0 1

aviation_community 56418 0.0575 0.2328 0 1

mfr 56418 0.0430 0.2029 0 1

Table 9. Descriptive Statistics, Prior AC Service SMCR, E3–E5 (All Observations) unemployment 156267 5.4550 1.0100 2.2 11.4

afqt 147435 58.5900 18.2000 30 99

unexcuse_12_mo 156473 0.7947 3.6160 0 48 SMCR_break_PS_gt1 156473 0.1321 0.3386 0 1

satyrs 146964 5.9520 1.6020 3 14 cpl 156473 0.2939 0.4555 0 1 sgt 156473 0.6544 0.4756 0 1 combat_arms 156473 0.3039 0.4599 0 1

aviation_community 156473 0.0922 0.2893 0 1

mfr 156473 0.0557 0.2293 0 1 pacificislander 156473 0.0031 0.0553 0 1

asian 156473 0.0270 0.1621 0 1

F. CHAPTER SUMMARY

In this chapter, we reviewed four model specifications and three different tour lengths for multivariate analysis using the standard normal cumulative distribution function, probit. The first model focuses on the primary research question, “what is the impact of activation on continuation rates for prior service SMCR unit personnel in the ranks of lance corporal through sergeant” and on the secondary research question regarding the effect of monetary incentives on continuation. The second model will be used to identify other significant predictors of continuation. The third and fourth models estimate these effects separately for prior RC and prior AC sub-groups. Lastly, this chapter reviewed the dependent variable, 12-month continuation rates, the hypothesized effects of the explanatory variables, and presented cross-tabulations of select variables.

The next chapter provides the results of the multivariate analysis followed by the conclusion and recommendations for future research.