Externalities and social preferences, such as altruism, play a key role in the choice of social interactions, which in turn affect the diffusion of a pandemic. We build a dynamic epidemiological model with endogenous social interactions in a frictional environment, also in a variant with heterogeneous agents and a network structure. Taking into account agents’ endogenous behavior and altruism generates markedly different predictions relative to a naïve epidemiological model with exogenous contact rates. Congestion and commitment inefficiencies arise, even under full altruism, and call for policy intervention. We derive the efficient allocation, and show how the Ramsey planner can mitigate the respective externalities.

This study explores the evolution of accounting research by utilizing an unsupervised machine learning approach. We aim to identify the latent topics of accounting from the 1980s up to 2018, the dynamics and emerging topics of accounting research, and the economic reasons behind those changes. First, based on 23,220 articles from 46 accounting journals, we identify 55 topics using the latent Dirichlet allocation model. To illustrate the connection between topics, we use HistCite to generate a citation map along a timeline. The citation clusters demonstrate the “tribalism” phenomenon in accounting research. We then implement the dynamic topic model to reveal the dynamics of topics to show changes in accounting research. The emerging research trends are identified from the topic analytics. We further explore the economic reasons and in-depth insights into the topic evolution, indicating the economic development embeddedness nature of accounting research.

This paper studies the role of social connections in shaping individuals’ concerns about climate change. I combine granular climate data, region-level social network data and survey responses for 24 European countries in order to document large information spillovers. Individuals become more concerned about climate change when their geographically distant friends living in sociallyconnected regions have experienced large increases in temperatures since 1990. Exploring the heterogeneity of the spillover effects, I uncover that the learning via social networks plays a central role. Further, results illustrate the important role of social values and economic preferences for understanding how information spillovers affect individual concerns.