The overall aim of this article is to examine whether and how increased service from the government affects citizen inputs to coproduction of public services. If public and citizen inputs are complementary, as assumed in most theories of coproduction (i.e., a mix of public and citizen input leads to a higher output than each one of them alone), increased public inputs will increase the marginal product of citizen inputs. Thus, if citizens perceive inputs to be complementary, an exogenous increase in government inputs should induce citizens to increase their coproduction efforts. On the other hand, if citizens perceive inputs to be substitutes, increased public inputs may crowd out citizen inputs. Most likely, different groups of citizens react differently to changes in public inputs. Questions of this sort have only to limited extent been empirically tested within the coproduction literature. This may be due to methodological difficulties of separating the effect of government initiatives from other causes that also influence citizen inputs to the public service production. We address these questions and methodological issues using a randomized field experiment, where public input was increased by assigning co-teachers to school classes. The experiment involves around 10,500 students from 231 schools, and measures citizen coproduction by the amount of time parents spend doing homework with their children. The effect of increasing school resources on parental caring is estimated using OLS regression for subgroups of children (girls/boys, high/low SES families, high/low ability etc.). In particular, we investigate whether increased school resources facilitates inclusion of vulnerable families in coproduction efforts. The results will provide new empirical evidence on intended as well as unintended effects of increasing the public side of coproduction.
