A recent survey of personnel in a hundred large organizations, to determine which outfits were best able to maintain high morale, included U.S. military services as well. After all the U.S. Department of Defense is the largest single employer on the planet. To the surprise of most everyone, these military organizations scored very high. The U.S. Air Force (345,000 employees) was number 5, the U.S. Army National Guard (350,000) was 7, the U.S. Marine Corps (202,000) was 8, the U.S. Navy (360,000) was 9, and the U.S. Army (550,000) was 11. The scale was 1-5, with the average score 3.34. The top 11 also included Google (number 1), 3M, ABN AMRO, DTE Energy, Qualcomm and LSI Logic. The scores for the top 11 ranged from 4.04 to 4.36.
The study used over a thousand surveys and other public data to measure five measures of employee satisfaction. These categories included; growth opportunity (lots of training and new tech all the time), pay (military pay is maintained at levels to comparable civilian work), benefits (excellent medical and retirement), work-life balance (not-so-good in wartime), promotion prospects (promotions come fast in wartime), senior management (not much better than civilian counterparts), job security (superior to civilian firms) and whether the employee would recommend his employer to others (very high for military personnel, and then there's the uniforms).
The U.S. military has been all-volunteer since the early 1970s, forcing the use of incentives to attract and retain qualified personnel. As a result, the U.S. armed forces became something of an elite organization. Military personnel are better educated, and in much better physical shape than their civilian counterparts (in terms of age). This has apparently helped morale quite a bit.
For more data see www.careerbliss.com/press/25-most-blissful-places-to-work/.