时间：2025年10月29日（周三）14:00-15:30

地点：北大国发院承泽园245教室

主持人：张丹丹、黄炜

参与老师：雷晓燕、李玲、刘国恩、易君健

主讲人：Wojciech Kopczuk，Columbia University

摘要：The title of the presentation is "Taxation and Business Organizational Forms." I will discuss different ways of taxing closely-held businesses and evidence on how they interact with measuring inequality. I'll then present evidence from our work-in-progress entitled "Business Organizational Forms and Taxation of High-Income Professionals: Evidence from Canadian Doctors" and it's joint work with Terry Moon (University of British Columbia) and Michael Smart (University of Toronto).  The abstract for this paper is as follows: Small businesses including high-income professionals choose to operate as corporations or passthrough entities such as sole proprietorships on the basis of non-tax and tax considerations. Incorporation may offer businesses lower effective tax rates on income earned and distributed to the owner-manager, as well as opportunities to defer taxes to the future. We show how taxes affect labor and investment decisions over the life cycle and derive a ``sufficient statistics'' formula for the impact of incorporation on social welfare. Using longitudinal administrative tax data in 2001-17, we study the businesses of Canadian physicians and dentists. We identify the causal effects of taxes using a triple-difference design that exploits a 2006 reform that facilitated incorporation by doctors in Ontario. incorporation rates in the treated group rose sharply after the reform compared to a matched control group of doctors in other provinces and business owners in other industries. Employment and business investment rose. Combined personal-plus-corporate incomes rose initially following the reform and then fell gradually for doctors in their 50s and 60s. Effective tax rates fell marginally, mainly due to the shifting of income to family members. Doctors accumulated substantial retained earnings inside their corporations, suggesting they are used as deferred-tax retirement savings vehicles. Taken together, these results are consistent with both tax avoidance through a corporation and real response via business expansion after incorporation

主讲人简介：

Wojciech Kopczuk is a Professor of Economics at Columbia University and a leading scholar in public finance. His primary research focuses on wealth and income inequality, taxation, and the economics of inheritances. He has made significant contributions through his work on top wealth shares, estate taxation, and business incomes, publishing extensively in top-tier journals such as the Quarterly Journal of Economics, Journal of Political Economy, and the American Economic Review.

Professor Kopczuk holds several key editorial and leadership roles. He is the Editor-in-Chief of the Journal of Public Economics and served as President of the International Institute of Public Finance from 2021 to 2024. His research excellence has been recognized with honors including the Peggy and Richard Musgrave Prize, an Alfred P. Sloan Research Fellowship. Through his influential research and professional service, he is a central figure in the analysis of tax policy and inequality.