We study the interplay between individuals' voluntary contributions to environmental protection and public environmental policy in a dynamic general-equilibrium model. To capture the observed discrepancy between the willingness of individuals to pay for public and private environmental protection, we treat the quality of the environment as a public good and assume that voluntary contributions are motivated by a `warm glow' of giving. We show that in the laissez-faire scenario without government intervention, the strength of warm glow negatively affects aggregate output and positively affects environmental quality in the long run. However, when the government intervenes and decides on environmental policy in the interests of individuals, the warm-glow strength has a negative long-run effect on both variables. Thus, our results suggest that advocating for private actions to ensure a better environment in the future may be counterproductive in the presence of public environmental policies.

We examine the long-run impact of unfunded social security on capital stock and wealth inequality in an overlapping generations (OLG) model where newborn individuals differ in their inheritance. In our model, individuals' decisions are subject to social comparisons, which can lead to overspending on personal consumption and result in zero bequests left within poor families. In this scenario, unfunded social security increases long-run wealth inequality by redistributing wealth from poor to rich families, who always leave bequests. However, it increases long-run capital stock, too. We also show that when none or all of the families leave bequests in the long run, our model predicts negative and neutral effects of social security on capital accumulation, in line with the standard OLG models of Diamond (1965) and Barro (1974). Thus, our results emphasize the need to account for heterogeneity in bequest behavior in the analysis of social security.

It is widely acknowledged that there is an urgent need for policies that can reduce greenhouse gas emissions. Yet, the policies implemented by governments are far from sufficient to reach their long-term climate targets. In this paper, we propose a theoretical framework to study the implications of political pressure on optimal climate policy. A key feature of the framework is its ability to capture dynamic inconsistency, which naturally arises from the long time horizon of climate policies and their susceptibility to modifications due to political pressure. Our findings offer a new rationale for why green lobbying can make pollution regulation less stringent. We also show that political pressure from the polluting sector leads to a higher rate of clean energy investment chosen by the government and can shift the energy mix towards renewables in the long run. Similarly, this long-run shift can be caused by political pressure from members of the public who care only about immediate consumption. 

This paper seeks to explain why annuity purchases are postponed to a later age. We consider an overlapping generations model with uncertain lifetime and two types of annuities. It is shown that, if the economy is dynamically inefficient, individuals demand annuities without delay. However, if it is efficient, annuity purchases are postponed. We also show that these results are robust to several extensions.