When thinking about global environmental policies, such as climate change mitigation and transnational biodiversity conservation, one of the most pressing concerns is an understanding of how individual public goods contributions change when benefits from public goods provisions cross national borders and generations. We run simultaneous intercountry laboratory experiments in Denmark, Spain and Ghana using a modified public goods game that allows present generation public good contributions to affect future generations. Present generation individuals can affect future generation individuals of the same or of a different nationality. The effect of present contributions on future generations can be one of two ways: the present can improve the future’s institutions by increasing the future’s marginal per capita return (MPCR) or increase the future’s income by increasing the future’s initial endowment. Our results show that: i) Danes and Spaniards contribute more to national rather than transnational public goods and ii) Danes and Spaniards contribute more to public goods provision when they are able to affect future generations. In particular, Danish contributions to transnational public goods increase when they are able to affect future institutions while Spanish contributions to both national and transnational public goods increase when they are able to affect future endowments.