北大经院工作坊第628场
A Tale of Two Thresholds: Dynamic Implications of Size-Based Policies
发展与公共财政工作坊
主讲人：Mazhar Waseem（University of Manchester）
参与老师：
（北大经院）刘冲、吴群锋、曹光宇
（北大国发院）李力行、席天扬、徐化愚、于航、王轩、易君健
时间：2023年4月19日（周三）16：00-17：00
形式：ZOOM会议
（发送邮件至 lujing@nsd.pku.edu.cn 获取线上会议链接）
主讲人简介：
Mazhar Waseem is a Reader (Associate Professor) of Economics at the University of Manchester. His research primarily focuses on Public Finance issues of emerging economies, especially on the behavior of economic agents to tax and transfer policies with a view to learn how the design of these policies, especially in weak enforcement environments, can be improved. He holds a Ph.D. in economics from the London School of Economics. He is a Research Associate at the Institute of Fiscal Studies, Research Affiliate at the Centre of Economic Policy Research (CEPR) and an editor of International Tax and Public Finance.
摘要：
Size-based polices, whereby firms smaller than a given size threshold are not required to remit taxes or comply with regulations, are ubiquitous, especially in developing economies. These policies distort firms size choices, incentivizing them to remain small. In this paper, we explore the dynamic implications of two size-based tax policies from Pakistan. Under the first policy, firms with profits below the income tax exemption threshold are not required to pay profit tax and under the second policy firms with annual turnover below the VAT exemption threshold are not required to remit VAT on their sales. Exploiting the universe of income tax returns filed between 2006 and 2020 and leveraging important tax reforms through which these exemption thresholds were moved more than once, we document six stylized facts on how size-based policies affect firm behavior. Using bunching and difference-in-differences frameworks, we then estimate the reduced-form effects of the policies, exploiting the movements of the two thresholds. Finally, we use the simulated method of moments to estimate a dynamic structural model incorporating non-linear taxation of firms observed in Pakistan. The model rationalizes our results and allows counterfactual policy analysis.
北大经院工作坊第629场
Content-hosting platforms: discovery, membership, or both?
微观理论经济学工作坊
主讲人：Tat-How Teh（香港中文大学（深圳）助理教授）
主持老师：
（北大经院）吴泽南、石凡奇
（北大国发院）胡岠
参与老师：
（北大经院）胡涛、吴泽南、石凡奇
（北大国发院）汪浩、胡岠
（北大光华）翁翕
时间：2023年4月20日（周四）10：30 -12：00
地点：北京大学经济学院302会议室
主讲人简介：
Tat-How Teh joined The Chinese University of Hong Kong (Shenzhen) as an assistant professor in economics in September 2021. His research interests are platform economics, consumer search, industrial organization theory, and, more generally, applied microeconomic theory. He has published articles in several leading economic journals, including RAND Journal of Economics, American Economic Journal: Microeconomics, and Games and Economic Behavior. His works have received the Concurrences Antitrust Writing Awards (academic articles) in 2023. He received his Ph.D. in Economics from the National University of Singapore in 2019.
摘要：
We develop a model that classifies platforms in the "creator economy"--- e.g., Youtube, Patreon, and Twitch---into three broad business models: pure discovery mode (providing recommendations to help consumers search for creators); pure membership mode (enabling individual creators to monetize their viewers through direct transactions); and a hybrid mode which combines both. Creators respond to platforms' decisions by individually choosing to supply content designed along a broad-niche spectrum, which involves a trade-off between viewership size and per-viewer revenue. These design changes create a trade-off between the platform's advertising revenue and transaction commission revenue. In a monopoly platform benchmark, moving from pure discovery to hybrid always increases platform revenue while making content weakly more niche. However, moving from pure membership to hybrid may reduce platform revenue if providing advertising is not sufficiently lucrative. In a duopoly setup, these tradeoffs can change substantially depending on the level of platform competition and homing behavior of creators and consumers.
北大经院工作坊第630场
Analyst Sentiment, Mispricing, and Over-Investment
（分析师情绪、错误定价与过度投资）
计量、金融和大数据分析工作坊
主讲人：Jun Tu（Singapore Management University）
主持老师：（北大经院）王熙
参与老师：
（北大经院）王一鸣、刘蕴霆
（北大国发院）黄卓、张俊妮、孙振庭
（北大新结构）胡博
时间：2023年4月21日（周五）10：00-11：30
形式：腾讯会议
会议号：508-649-581
主讲人简介：
Professor Jun Tu is Assistant Professor of Finance (from July 2004 to June 2012) and Associate Professor of Finance (from July 2012) at the Singapore Management University (SMU). Prof Tu has served as the center director for the Centre for Asset Securitisation and Management in Asia at SMU from 2012 to 2014. He has been serving as Associate Editor for Journal of Economic Dynamics and Control (2018 - present), Subject Editor for the Emerging Markets Finance and Trade (2013 - present), and Associate Editor for China Finance Review International (2020 -present). In addition, prior to SMU, he was studying as a Finance PhD student at Washington University in St. Louis. His main research interests are in Behavioral Finance, Empirical Asset Pricing, FinTech, Corporate Finance, Media and Asset markets, Big Data and Machine Learning, Textual Analysis, Financial Econometrics. He is a receiver of several awards, including The Most-Cited Paper Reward (2015-2016) at Review of Financial Studies, Lee Foundation Fellowship for Research Excellence at SMU, Sing Lun Fellowship, Pacific Basin Finance Journal Prize (First Prize), and Research Fellowship at Washington University in St. Louis. His research articles have been published in top academic journals, including Journal of Finance, Journal of Financial Economics, Review of Financial Studies, Journal of Financial and Quantitative Analysis, and Management Science. Besides academic impacts, his research has also been synthesized by leading industry-oriented journals, such as The CFA Digest, Citibank/UBS Reports.
摘要：
We create a market-level analyst sentiment index from firm-level textual tones in analyst reports and compare it to existing investor sentiment indices. High investor sentiment typically corresponds with high analyst sentiment, leading to market overpricing. Our analysis shows that the analyst sentiment index negatively predicts aggregate stock market return. Existing investor sentiment indices have been relatively flat in recent years, casting doubt on their ability to reflect underlying investor sentiment. Conversely, the analyst sentiment index still fluctuates and may better reflect underlying investor sentiment. Additionally, analysts may give less favourable tones when manager sentiment is high, which can mitigate inefficient over-investment due to managers' overoptimistic views.
北大经院工作坊第631场
空气污染对农业生产效率的影响分析
生态、环境与气候变化经济学工作坊
主讲人：陈晓光（西南财经大学教授）
主持老师：（北大经院）季曦
参与老师：
（北大经院）章政、张博、李虹、张鹏飞、刘政文、梁远宁、庄晨
（北大国发院）徐晋涛、王敏、邢剑炜、易媛媛、龙显灵
（北大现代农学院）刘承芳、侯玲玲、解伟、王悦
时间：2023年4月21日（周五）12：00-14：00
地点：北京大学经济学院302会议室
主讲人简介：
陈晓光，西南财经大学教授，国家自然科学基金优秀青年科学基金获得者。于北京大学获得学士学位，美国伊利诺伊大学香槟分校获得博士学位。从事环境经济学、农业经济学和运筹学领域的理论和应用研究，13篇论文发表于Nature正刊、《经济研究》、American Journal of Agricultural Economics、Journal of Environmental Economics and Management和Transportation Science等领域顶级期刊。主持3项国家自然科学基金项目。入选爱思唯尔2020中国高被引学者（理论经济学）。
摘要：
本文分析包括气候变化和空气污染在内的多种环境因素变化对农业生产效率的影响。研究发现，自2013年起中国实施的空气污染治理政策有助于推动农业的高质量发展。
供稿：科研与博士后办公室
美编：兮哲
责编：度量、雨禾、雨田
