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Research Brief


A study of Army Reserve Component (RC) units found that personnel instability is widespread—driven mostly by soldier losses and nondeployers—and affects training prior to deployment. Analysis of the probable effects of possible policy interventions showed that, even with multiple policy changes and reasonable degrees of success, the RC will have to live with considerable instability in the run-up to mobilization and deployment. The study offers some short- and longer-term options for responding to the situation.

Military forces place high value on unit stability—keeping a unit's membership constant over time—particularly in units deploying to a theater of operations. Yet, Army units, including active Army and Reserve Component (RC) ones, typically have considerable personnel turbulence as they approach mobilization and deployment. Some members leave the unit or do not deploy with it, and new personnel are transferred in ("cross-leveled") to reach the unit's target for deploying strength. Thus, the unit must repeat some elements of training for the newcomers. This situation is widely viewed as a potential problem, particularly in reserve units, which have limited time to train before mobilizing.

Drawing on longitudinal data from U.S. Department of Defense (DoD) monthly records for all personnel in any Army component from 1996 through 2008, RAND researchers looked at the extent of the problem, along with its causes and potential policy solutions. The analysis—which included infantry battalions, military police (MP) companies, and truck companies as representatives of combat, combat support, and combat service support units, respectively—focused on 153 RC unit deployments from 2003 through 2008, representing more than 40,000 authorized positions.

Instability Is Widespread

Of all the soldiers who actually deployed with the units studied in detail, 40–50 percent were new arrivals who had been in the unit for less than a year. This picture of instability was widespread across all types of deploying units (including active units), affecting all grade levels—junior enlisted personnel, noncommissioned officers, and officers. In fact, officer instability was the highest of all grade groups, because officers tend to be transferred out of a deploying unit into another unit.

Several Factors Account for Instability

The primary factors creating instability were soldiers moving to another unit or leaving the service and personnel who did not deploy with their unit (nondeployers). Across the unit types studied, between 25 and 40 percent of personnel assigned to the unit 12 months before mobilization had left during the subsequent year. But these loss rates may be more benign than the numbers suggest: They were not higher than in a previous baseline period, and they did not rise appreciably as mobilization approached. And many unit losses were moves to other Army units rather than Army losses. In fact, those same soldiers often deployed with their new unit, sometimes even before the source unit deployed.

About 30 percent of soldiers in the RC units on the deployment date (D-day) were nondeployers. Many conditions contributed to this picture. Some did not deploy with their unit but then moved to another unit. Some deployed later. Some stayed at the home station as part of a rear detachment. Some had prior activations and so were probably exempt from another near-term deployment. And some were new recruits who had not yet completed initial training.

In some cases, losses or nondeployers represent an Army accommodation to the service member's personal circumstances or hardship; in other cases, they arise from deliberate Army actions (e.g., to fill higher-priority deploying units) or from conditions normal to the reserves (e.g., the presence of untrained new recruits, who cannot be deployed until they finish training).

Instability Affects Training Prior to Deployment

The rapid buildup of personnel begins four to six months before mobilization. But units have often been conducting important training events for 12 months or more before mobilization. When that training is done early, the new arrivals miss key events, which means that the unit must arrange training for them. In some cases, training on significant subjects—such as weapon qualification, combat lifesaver training, urban warfare techniques, and dealing with improvised explosive devices—was conducted early enough that 30 to 50 percent of the deployers would have missed them. That pattern was common across all types of units studied. Still, the system has proved resilient: Ninety-five percent of those who deployed were in place by the mobilization point, the Army did complete training of newcomers, and no theater arrival dates were slipped.

Units recognize that instability affects training efficiency and especially scheduling. Thus, many units tried to schedule much of their training closer to mobilization, when unit manning was more stable.

Options for Managing Instability

Many different groups with different conditions contribute to instability, but most represent just a small fraction of the problem, and many would be difficult to affect by policy. Analysis of the probable effects of possible policy interventions showed that, even with multiple policy changes and reasonable degrees of success, the RC will have to live with a substantial amount of instability in the run-up to mobilization and deployment.

Of course, other alternatives exist, but each comes with its own trade-offs. For example, DoD could cluster training just before mobilization, ensuring that most soldiers are together in the unit for training and avoiding the inefficiencies of doing training earlier. But this concentrates intensive training into a short period just before mobilization and could result in lower participation rates if the time demands are too high.

Alternatively, DoD could postpone some training until after mobilization, accomplishing more training when all deploying solders are present, relieving pressure on the pre-mobilization period, and potentially offering greater efficiencies by operating in centralized facilities. Recent data on unit preparation and deployment suggest that more training could be done after mobilization while still maintaining planned levels of "boots-on-the-ground" time, but such a change would need to be tested. If it required more time, DoD would face two less attractive options: Increase the duration of mobilization (keeping soldiers away from their homes and civilian jobs for a longer continuous period), or reduce time in theater (requiring a faster unit turnover rate in theater and thus more units to cover a given period of operations).

For the longer term, DoD might experiment with some more-aggressive initiatives that aim to foster better unit-level retention, control interunit moves, lower vacancies through intensified recruiting, accelerate initial training, and enhance medical and dental screening or treatment. Also, it might try initiatives to enhance training efficiency, such as more-centralized training, greater use of mobile training teams, and distributing individual training to personnel who will move into a deploying unit just before mobilization. Such initiatives could require substantial investments with uncertain payoffs, so they would need to be tested for credible evidence of their actual effects and costs.

This report is part of the RAND research brief series. RAND research briefs present policy-oriented summaries of individual published, peer-reviewed documents or of a body of published work.

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