Union Membership and Charitable Giving in the United States
利用2001-2011年美国面板数据，发现工会会员比非会员更可能捐赠且捐赠更多，而搭便车者最不慷慨；加入工会会促进捐赠，成为搭便车者则减少捐赠行为。
Using U.S. panel data from 2001–2011, the authors examine general differences in charitable giving between union members, free-riders, and the nonunionized. Results indicate that union members are more likely to give and to give more to charity relative to the nonunionized, whereas free-riders are the least generous. Similar effects are found when examining the question of who joins a union or who becomes a free-rider: joining a union positively affects charitable giving, while becoming a free-rider makes individuals’ behavior less charitable. Evidence also suggests that the positive effect of union membership on giving does not diminish over time. Taken together, these results provide new evidence that union membership generates civic engagement in the form of charitable behavior; results also suggest the need to further investigate the civic behavior of free-riders.