This study utilizes data from a recent Danish survey to investigate, which social mechanisms that can explain volunteering in Denmark. I take two opposed theories as my starting point. Resource theory claims that people who are endowed with more personal, social, and cultural resources are more likely to volunteer, and volunteer more hours. Cost-benefit theory, on the other hand, argues that rational actors will weigh the cost and benefits of volunteering, and participate and volunteer more hours if the benefits exceed the costs.
Sociologists often reject cost-benefit theory, because empirical research consistently show that people with more personal resources, and hence higher opportunity costs of volunteering, are in fact more likely to participate. I argue, however, in favor of a “low-cost hypothesis”, where the decision to participate is considered a low-cost-decision. This entails that opportunity costs are expected to play only a minor role in terms of explaining the participation decision. Instead, I argue that the decision, which can be expected to bring about high opportunity costs, is the decision to volunteer a substantial amount of hours. Thus, I expect that cost-benefit theory will fail to explain the participation decision, but I expect cost-benefit theory to have more explanatory power in terms of explaining the amount decision.
In order to test this thesis, I argue that work hours, amount of time spent on informal helping activities, the presence of small children in the household, and personal income can be viewed as proxy variables for the opportunity costs of volunteering. Thus, I do not necessarily expect these factors to be negatively correlated with the participation decision; however, I do expect them to be negatively correlated with the amount decision.
Previous studies of volunteering have often relied on a standard Tobit-model. The Tobit-model assumes that the actor has a latent propensity to volunteer a certain amount of time, which is realized when the latent propensity reaches a threshold value. Thus, the Tobit-model implicitly assumes that the same explanatory factors can explain both the participation decision and the amount decision. Moreover, the model restricts the explanatory variables to have similar effects on both decisions. In line with my theoretical framework, I argue that the latter presumption is too restrictive. As an alternative, I argue that a more realistic model of the actor’s actual decision-making process is a two-stage model, which separates the participation decision from the amount decision. Moreover, I argue that the participation decision and the amount decision are likely to be dependent even after conditioning on covariates; this fact calls for a selection type of two-stage model.
The empirical analysis unambiguously confirms the inferiority of the Tobit-model and points to the two-stage selection model as a better alternative. Utilizing a two-stage selection model, I find that work hours and the presence of small children in the household are indeed negatively correlated with the amount decision. However, I do not find evidence of a negative correlation between time spent on informal helping activities and the amount decision, nor do I find a negative correlation between personal income and the amount decision.
Even though evidence is mixed, I think the results render it probable that even though cost-benefit theory often fails to explain the participation decision it has more explanatory power in terms of explaining the amount decision. Thus, I argue that when sociologists routinely reject cost-benefit theory it might have to do with a tendency to study the participation decision only, or a long standing preference towards the standard Tobit-model, which by construction fails to separate the participation decision and the amount decision.