Effect of reciprocity on public opinion of international climate treaties: experimental evidence from the US and China

This study reports survey results of American and Chinese citizens administered to determine the effect of reciprocity and the absence of reciprocity on public support of international climate treaties. American and Chinese college students and adults were surveyed about their support for signing an international climate treaty including commitments to reduce their greenhouse gas emissions, conditional on the other country signing the same treaty or not. This study finds knowledge of other-country non-support on average decreases cooperative behaviour among all age groups in both the US and China. Knowledge of China’s support for the treaty is found on average to increase support among American adults, while having no noticeable effect on average support among American college students. Chinese citizens are found to not respond positively to reciprocity. Although not statistically significant at conventional significance levels, knowledge of the US’s support is found on average to decrease support among Chinese college students and adults. <b>Key policy insights</b>To increase support for international climate treaties, knowledge that another major emitter will sign the treaty does not unanimously increase domestic support.Knowing the other country will not sign the treaty decreases domestic support for signing an international climate treaty for both Americans and Chinese, relative to not being told about the other country’s decision to sign the treaty.Knowing China will sign an international climate treaty on average increases American adult support for signing the same treaty, while American college student support is unaffected.Although not statistically significant at conventional significance levels, knowing the US will sign an international climate treaty on average decreases Chinese support for signing the same treaty.Policy-makers pursuing increased international support of climate treaties by first getting support from countries with substantial historical emissions might deter international support if little attention to fairness concerns is given. To increase support for international climate treaties, knowledge that another major emitter will sign the treaty does not unanimously increase domestic support. Knowing the other country will not sign the treaty decreases domestic support for signing an international climate treaty for both Americans and Chinese, relative to not being told about the other country’s decision to sign the treaty. Knowing China will sign an international climate treaty on average increases American adult support for signing the same treaty, while American college student support is unaffected. Although not statistically significant at conventional significance levels, knowing the US will sign an international climate treaty on average decreases Chinese support for signing the same treaty. Policy-makers pursuing increased international support of climate treaties by first getting support from countries with substantial historical emissions might deter international support if little attention to fairness concerns is given.

本研究报告了针对美国与中国民众开展的调查结果，旨在探究互惠行为与非互惠行为对公众支持国际气候条约的影响。本次调查覆盖美国和中国的大学生及成年人群体，询问了他们在对方国家签署或不签署包含温室气体减排承诺的国际气候条约这一条件下，自身对签署该条约的支持意愿。本研究发现，获悉对方国家不支持该条约，平均而言会降低中美两国所有年龄段群体的合作意愿。研究显示，得知中国对该条约的支持态度，平均而言会提升美国成年人群体的支持率，但对美国大学生群体的平均支持率无显著影响。此外，中国民众并未对互惠行为表现出正向响应。尽管在常规显著性水平下未达到统计学意义，但平均而言，得知美国将签署该国际气候条约，反而会降低中国大学生与成年人群体的支持意愿。<b>关键政策洞察</b>若想提升国内民众对国际气候条约的支持度，知晓另一主要排放国将签署该条约，并非总能普遍提升国内支持率。相较于未获知对方国家签署条约的决策，得知对方国家将不签署该条约，会同时降低美国与中国民众对签署国际气候条约的国内支持率。得知中国将签署国际气候条约，平均而言会提升美国成年人群体的支持意愿，但对美国大学生群体的支持率无显著影响。尽管在常规显著性水平下未达到统计学意义，但得知美国将签署国际气候条约，平均而言反而会降低中国民众（包括大学生与成年人）对签署该条约的支持意愿。若政策制定者试图通过先获得历史排放大国的支持，来提升气候条约的国际支持度，却未充分考量公平性关切，则可能反而阻碍国际社会对该条约的支持。若想提升国内民众对国际气候条约的支持度，知晓另一主要排放国将签署该条约，并非总能普遍提升国内支持率。相较于未获知对方国家签署条约的决策，得知对方国家将不签署该条约，会同时降低美国与中国民众对签署国际气候条约的国内支持率。得知中国将签署国际气候条约，平均而言会提升美国成年人群体的支持意愿，但对美国大学生群体的支持率无显著影响。尽管在常规显著性水平下未达到统计学意义，但得知美国将签署国际气候条约，平均而言反而会降低中国民众（包括大学生与成年人）对签署该条约的支持意愿。若政策制定者试图通过先获得历史排放大国的支持，来提升气候条约的国际支持度，却未充分考量公平性关切，则可能反而阻碍国际社会对该条约的支持。