題  目🔨🏬：How Mega is the Mega?

Measuring the Spillover Effects of WeChatUsing Graphic Model

報告人：竇一凡副教授   復旦大學管理凯捷

時  間：2021.12.1 10:30-11:30

地  點：線上騰訊會議419 440 452

Abstract

WeChat, an instant messaging app, isconsidered a mega app because of its dominance in terms of use among Chinesesmartphone users. Little is known, however, about its externality in thebroader app market. This work estimates the spillover effects of WeChat on theother top 50 most frequently used apps in China, using users’ weekly app usagedata. Given the challenge of determining causal inference from observationaldata, we apply a graphical model and an econometric method to estimate thespillover effects in two steps: (1) we determine the causal structure byestimating a partially ancestral dia- gram, using a fast causal inferencealgorithm; and (2) given the causal structure, we find a valid adjustment setand estimate the causal effects by an econometric model with the adjustment setfor controlling noncausal effects. Our findings show that the spillover effectsof WeChat are limited; in fact, only two other apps, Tencent News and Taobao,receive positive spillover effects from WeChat. In addition, we show that ifresearchers fail to account for the causal structure that is determined fromthe graphical model, it is easy to fall into the trap of confounding bias andselection bias when estimating causal effects. The findings generate managerialimplications in terms of app usage patterns, strategic management of mega appson an app platform, and app promotional strategies for app platform managersand app developers.

主講人介紹：竇一凡，復旦大學管理凯捷信息管理與信息系統系副教授、博士生導師🌳♠︎。他的主要研究興趣是電子商務、平臺模式和數字虛擬產品的經濟學問題🍢，他的研究受到國家自然科學基金優青項目資助。他目前是信息系統領域國際頂級期刊《Information Systems Research》的Associate Editor。