2023年9月，北京大学现代农学院助理教授、中国农业政策研究中心研究员、现代农学院博士生导师黄开兴以第一作者兼通讯作者身份与合作者在国际学术期刊Journal of the Association of Environmental and Resource Economists（JAERE）上在线发表题为“Positive Rainfall Shocks, Overoptimism, and Agricultural Inefficiency in China”的研究论文。JAERE是资源与环境经济学领域公认的国际顶级期刊，位于SSCI经济学大类Q1区（12/373），影响因子5.167。

论文主要内容如下：This study identifies overoptimism of farmers as an important cause of factor misallocation and inefficiency in agriculture. Annual deviation of rainfall from the local normal is exogenous, unanticipated, and transitory, but we find that farmers substantially adjust labor and land allocation in response to a lagged positive rainfall shock. By examining the response of more than 10,000 farmers in China over 11 years, we show that a lagged positive rainfall shock significantly reallocates labor from high-income off-farm work to low-income farm work, reallocates farmland from high-productivity farmers to low-productivity farmers, and reduces the average rural income by 8.1 percent. We also found that these effects are primarily driven by the irrational responses of low-productivity farmers and that farms with good irrigation conditions are generally not damaged.