Determinants of collective action by farm producers: A meta-analysis of the likelihood of co-operative membership
对168项研究进行元分析，发现性别、年龄、经验、教育、家庭规模、农场规模、牲畜规模和信贷获取显著正向影响合作社成员可能性，但效应量较小，且异质性难以用研究特征解释。
Collectively owned and controlled by farm producers, co-operatives have been prominent and successful in many countries. The empirical literature on co-operatives is extensive, part of which considers the various determinants of co-operative membership. However, the evidence is mixed and scattered, which warrants a meta-analysis to help inform market and policy initiatives to increase the incidence of collective action by farm producers. Our search yielded 168 studies, 213 model results, and 924 effect size estimates for the ten most common determinants: gender, age, experience, education, household size, farm size, herd size , off-farm income, credit access, and market distance. On the basis of random-effects model results, eight of the ten determinants (excluding off-farm income and market distance) have a positive and significant effect on the likelihood of co-operative membership at the 99 % confidence level. Thus, farm producers who are small, female, young, inexperienced, uneducated, or credit-constrained are less likely to obtain co-operative membership. However, the effect size magnitudes are arguably small; effect size dispersions are not explained significantly by common study-level characteristics such as location (i.e. continent) or commodity sector (e.g. coffee). Information of local contexts is necessary to better understand heterogeneity in effect size observations.