Climate policy may crowd out green values and what to do about it

Conventional approaches to policy design fail to recognise the plasticity of citizens’ beliefs and social preferences. Based on a representative sample from Germany, this column shows that mandated carbon-reducing lifestyle changes such as limiting heating and the use of cars in city centres may crowd out pre-existing green values. Effective climate policy design requires recognising that (a) to succeed, essential policies including bans, carbon taxes, and the promotion of new technologies must be both implementable and politically sustainable, entailing (b) a critical role for citizens’ green values, which (c) may be either diminished or cultivated, depending on policy design.

In the US and other countries during the covid pandemic, hostility towards mask and vaccination mandates appears to have spilled over to generalised distrust of health professionals and eventually to governments and the entire scientific community. As climate policymakers are forced to take increasingly stringent steps, we wondered if a similar reaction might occur, and if so, what might be the lessons for effective climate policy design. 

“Climate change, biodiversity loss, antibiotic resistance, and other global challenges pose major collective action problems…[but] policy can support social norm changes, helping to address even global problems”, write Karine Nyborg, Kenneth Arrow, Paul Erlich, Simon Levin and other leading climate scholars. But a concern raised by these authors, for which we provide evidence here, is that poorly designed policies may have the opposite effect: “legal and institutional measures may turn virtuous cycles into vicious ones” (Nyborg et al. 2016). 

We illustrate the practical importance of this possibility by the case of mandates – particularly those intended to promote more carbon-reducing lifestyles, such as limits on heating, meat consumption, the use of cars, and short-haul flights. We show that mandated measures are often experienced as restricting one’s personal autonomy, evoking opposition (termed ‘control aversion’ by behavioral economists and ‘reactance’ by social psychologists; see Brehm 1966, Falk and Kosfeld 2006, Schmelz 2021, Schmelz and Bowles 2022). The result is not only to impede or possibly even reverse the intended effect of the policy, but likely also to undermine support for society-level other measures essential to controlling emissions.

Climate policies that crowd out green values: Evidence

To assess the practical importance of these concerns, we surveyed a representative sample of 3,306 Germans on their responses to policies to promote less carbon-intensive lifestyles, conditional on their being either enforced or instead recommended but voluntary (Schmelz and Bowles 2026). 

In designing our survey, we were careful to distinguish a person’s pro or con attitudes towards their own adopting the behaviour targeted by the policy (“being okay with it” or not) from either support for the policy or compliance with the law in the case of an enforced mandate or ban. We asked, for example: “To what extent do you agree with foregoing the use of a car in city centres if … not using a car in city centres is strongly recommended by the government, but remains voluntary? … a ban on cars in city centres (apart from exceptional cases) is introduced and checked by the government?” Answers were given on a five-point Likert scale ranging from 0 (“not agree at all”) to 4 (“fully agree”), which we term the level of agreement. We measure the extent of control aversion by the Likert scale difference in agreement induced by the absence or presence of enforcement. 

Greater agreement in the case of an enforced rather than a voluntary policy reflects crowding-in, which we would expect to be common where the action targeted by the policy is a costly contribution to a public good. Behavioural experiments indicate that many people are conditional cooperators (Falk et al. 2001): they willingly contribute to a public good as long as they believe that most others will as well. Policies that include monitoring and penalties for non-compliance would appeal to these conditional cooperators, because they fear that their cooperativeness will be taken advantage of by free-riders who reap the benefits of the public good without contributing (Shinada and Yamagishi 2007, Rustagi, Engel et al. 2010). If conditional cooperators are prevalent, we would expect that enforced mandates would make adopting green lifestyles more attractive. 

This is not what we found. 

The pie charts in Figure 1 show that control-averse responses are frequent across all policies (orange slices). There are also some who exhibit crowding-in, responding positively to enforcement (blue slices), possibly conditional cooperators given our above conjecture; but these are at most 11%.   

Figure 1 Responses to voluntary and enforced green lifestyle changes

Notes: Pie charts show the shares of types of responses to enforced versus voluntary policies. Responses to enforcement are negative (reflecting control aversion or crowding-out) if agreement is lower in case of enforced rather than voluntary policies, and analogously for positive responses (i.e., crowding-in). Cumulative distributions show agreement in case of enforced (red) vs. voluntary (blue) policies. For example, the cumulative distributions in panel (a) show the percentage of respondents who fully agree (agreement level 4) with limiting room temperature if it is enforced or voluntary, that is, 15% or 43%, respectively. The sum of those expressing agreement levels 3 and 4 amounts to 25% or 63%, respectively, in the enforced or voluntary cases. Strongest opposition (agreement level 0) was expressed by 43% or 11%, respectively, if enforced or voluntary (the final step on the right in the left graph).

Figure 1 also shows cumulative distributions of agreement under enforced (red) versus voluntary (blue) policies. Across all domains, a majority of respondents agree with adopting the behaviour if the policy is voluntary (blue step functions, Likert levels 3 and 4). But this is not the case for any of the mandated policies (red step functions). Across all four policies, enforcement provokes opposition (levels 0 and 1) from a minimum of one-fourth (no short haul flights) to a maximum of three-fifths (restricting meat) of the sample.

The area between the blue and red step functions is what we call the ‘cost of control’, measured in terms of citizens’ attitudes as the average difference in agreement between the voluntary and enforced cases. The measure captures both the frequencies of types of responses to control (as indicated by the pies in Figure 1) as well as the different strength of their responses in the two cases (the step functions). By this measure, control aversion with respect to green lifestyle mandates is more than 50% greater than the similarly measured reactions to covid mandates that we also report in Schmelz and Bowles (2026, not shown here). 

As expected from cross-national and other evidence (Dechezlepretre et al. 2025), an important predictor of agreement in both the voluntary and enforced cases is the belief that the targeted behaviour is an effective way to address the climate challenge. In most cases, belief in policy effectiveness also strongly mitigates control aversion. Exceptions are policies likely to be seen as intrusive on one’s private sphere: examples are limiting meat consumption and home heating. For all of the climate policies, the respondents’ perception that an enforced policy “restricts my freedom” is the most important predictor of control aversion.

Behavioural policy design: Taking account of the plasticity of citizens’ beliefs and values

Addressing these concerns requires a reconsideration of the widely used economic approach to policy design (Laffont 2000). This is based on the idea that a government with extraordinary implementation capacities introduces incentives and constraints to modify the behaviour of citizens, who are presumed to have given beliefs and self-interested preferences. A quite different approach follows if one recognises that policy effectiveness depends on a combination of enforcement and voluntary compliance on the part of civic-minded citizens, the extent of the latter depending on social norms that may be undermined by the policy. 

Figure 2 presents both the conventional mechanism design approach and our proposed extensions that recognise the importance and plasticity of citizens’ values and beliefs along with the requirement that policies themselves must be sustainable. In the standard economic approach, based on the two causal arrows in the upper part of Figure 2, the policymaker implements a set of incentives (including penalties for violating prohibitions) to alter the expected economic costs and/or benefits of some targeted pro-social or pro-environmental action, which then induce the citizen to take the targeted action.

However, as our evidence shows, policies may affect not only the material benefits of taking an action, but also citizen’s values (negatively or positively, represented by minus and plus signs on the dashed purple arrow). In Figure 2, the crowding-out effect of a ban on car use (shown in Figure 1c) is represented by the minus sign on the purple arrow, indicating a negative effect. In the standard approach, the policy designer does not take account of these crowding-out or crowding-in effects either because the citizens’ values motivating the targeted green action in the absence of the policy are assumed to not exist or, if they do, are assumed not to be affected by the policy.

Figure 2 Policy effects on targeted pro-environmental actions, mediated by incentives and values 

Note: The black labels represent the general case. The green labels illustrate an application of one of our empirical results, namely the control-averse reaction to a ban on cars in cities. The purple dashed arrow shows what is neglected in the conventional approach: the effect of the policy on citizen’s values. A ban on using cars, our evidence suggests, could have a negative effect on citizen’s green values (the minus sign on the purple arrow) which would then promote less green lifestyle decisions (e.g. using a car more, where permitted). Less green values could also alter citizens’ political activities, both unrelated to cars (e.g. reduced support for a carbon tax) and the political sustainability of the car ban itself (shown by the bottom arrow).

Also shown in Figure 2 are possible adverse effects of incentives on citizens’ values that spill over to other environmental actions. For example, a control-averse reaction to a car ban may degrade citizens’ pro-environmental policy preferences and undermine support for the political movements advocating them. This may compromise citizens’ future advocacy in support of the car ban itself, represented by the lower arrow from citizens’ political action to policy.

Sustainable policies to mitigate climate change ideally crowd in green values

The legal scholar Eric Posner, writing about climate policy, explained how this might occur: “The law is always imposed against a background … of non-legal regulation… legal intervention will undermine or enhance the background social norms… The desirability of a proposed legal rule, then, depends on … the extent to which [it] would interfere with those non-legal systems” (Posner 2000).

We have documented a source of policy design failure illustrating Posner’s warning. Control-averse responses to mandates could reduce or even reverse the intended effects of policies to promote green lifestyle changes and instead cultivate anti-environmentalist values more generally, making the policies vulnerable to political reversal in the long run. 

To mitigate climate change, then, policy designers need to ensure that climate policies are themselves sustainable. Beyond mitigating or avoiding the crowding-out we have documented, well-designed policies should aim at cultivating and enhancing the values and beliefs essential to sustainable climate mitigation. Both experimental and field evidence point to successful examples of policies that can crowd in green values (Galbiati and Vertova 2008, Bowles and Polania-Reyes 2012, Galbiati and Vertova 2014, Grillos, Bottazzi et al. 2019). The small tax on plastic grocery bags imposed in Ireland in 2002 along with the publicity surrounding it, for example, virtually eliminated their use, apparently by heightening the salience of green values (Rosenthal 2008). 

Bringing these aspirations to practice requires an empirically based dynamic approach to policy design recognising that (a) successful policies must be both implementable and politically sustainable in a liberal democracy and (b) the resulting critical role of citizens’ green values, which (c) are not given but may be either diminished or cultivated by climate policy design. 

Studies by economists concerning policy design with endogenous green preferences (Mattauch, Hepburn et al. 2022, Besley and Persson 2023) will assist in addressing this challenge, as will the recent literature on endogenous preferences in economics more generally (Kreps 2023, von Weizsäcker 2024, Robson and Samuelson 2026). 

Source : VOXeu