Understanding social networks.

• Author: Costa, Dora L.

Heroes and Cowards: The Social Face of War

When are men willing to sacrifice for the common good? What are the benefits to men of friendship ? How do communities deal with betrayal? And what are the costs and benefits of being in a diverse community? Matthew Kahn and I answer these questions in an interdisciplinary book, Heroes and Cowards: The Social Face of War (forthcoming, Princeton University Press for NBER). Building on a series of joint NBER Working Papers, we weave a single narrative from the life histories of 41,000 Union Army soldiers, diaries and letters, and government documents.

One summer we both read Robert Putnam's thought-provoking book Bowling Alone (2000). We were fascinated by Putnam's account of the decline in American civic engagement over time. Putnam emphasized the growing popularity of television as a pivotal cause of the decline in community participation, but we wondered whether an unintended consequence of the rise of women working in the paid labor market was that PTAs and neighborhood associations lost their "volunteer army." We started to write a paper testing whether the rise in women's labor force participation explained the decline in residential community participation. (1) To our surprise, we found little evidence supporting this claim. Instead, our analysis of long-run trends in volunteering, joining groups, and trust suggested that, all else equal, people who live in cities with more income inequality were less likely to be civically engaged. These results contributed to a growing literature in economics documenting the disturbing fact that people are less likely to be "good citizens" when they live in more diverse communities.

Our early work on community participation attracted academic and popular media attention. Although we were flattered, we were aware that our measures of "civic engagement" bordered on "small potatoes." We were examining low stakes outcome measures such as entertaining in the household, joining neighborhood associations, and volunteering for local clubs.

In the summer of 2001, we realized that the American Civil War, 1861 to 1865, provided the ideal "laboratory." The setting was high stakes--roughly one out of every six Union Army soldiers died during the war. Unlike people in civilian life today, Union Army soldiers could not pick and choose their communities. Even when they signed up with friends, some men ended up in homogenous units and others in heterogenous units and they could not leave their units unless they deserted. Their "communities" were the roughly 100 men in their units--men they lived with 24 hours a day.

We answer the question of when men are willing to sacrifice for the common good by examining why men fought in the Civil War. (2) During this war most soldiers stood by their comrades even though a rational soldier would have deserted. Punishments were too rare and insufficiently severe to deter men from deserting. What then motivated these men to stand their ground? Was it their commitment to the cause, having the "right stuff," high morale, officers, or comrades? We examine all of these explanations and find that loyalty to comrades trumped cause, morale, and leadership. But loyalty to comrades extended...