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セミナー予定 (2026年度 秋)

Seminar Schedules (AY2026 Autumn)

Lester Lusher (University of Pittsburgh)

日時 date：2026年10月15日（木 Thurs） Google Calendar

時間 time：13:00-14:30 

タイトル title：When Samples Shape Significance 

発表言語 language：ENG

会場 venue：教授研究棟 03-G会議室  Room 03-G in Research Building

概要 abstract ：Random sampling yields unbiased estimates, yet sampling variation alone can produce incorrect conclusions. Using a setting where repeated draws from the same data-generating process are observable, we replicate findings from 24 papers in top economics journals and re-estimate each result using 40 independent resamples. Across 3,640 resampled results, t-statistics shrink by 31%, frequently leading to lost significance. Proxies for researcher degrees of freedom and sampling noise predict reduced significance. Our exercise provides novel evidence quantifying the effect of sampling variability on empirical research and highlights how statistical evidence can vary even when holding research design fixed.

渡辺 安虎 (東京大学 大学院経済学研究科、公共政策大学院)

Yasutora Watanabe( Faculty of Economics and Public Policy, University of Tokyo )

日時 date：2026年10月22日（木 Thurs） Google Calendar

時間 time：16:30-18:00

タイトル title：Household Production and Asymmetric Information (joint with Naoko Hara) 

発表言語 language：TBA

会場 venue：教授研究棟 03-G会議室  Room 03-G in Research Building

概要 abstract ：We study how endogenous asymmetric information within households shapes labor

supply, home production, and welfare. Using Japanese survey data that record spousal earnings disclosure, we document two facts: non-disclosure is associated with allocations consistent with free-riding in household public-good provision, and disclosure is gendered, with wives less likely and husbands more likely to disclose high relative earnings.

We estimate a two-stage model in which spouses choose whether to disclose wages before contributing noncooperatively to a household public good. Non-disclosure shifts posterior beliefs and contribution incentives. Full disclosure yields small aggregate allocative welfare gains but sharper distributional effects, especially under mutual non-disclosure. Noncooperative provision accounts for most welfare loss. 

Sueyoul Kim (Korea Development Institute）

日時 date：2026年10月29日（木 Thurs） Google Calendar

時間 time：16:30-18:00

タイトル title：Does Generative AI Crowd Out Human Creators? Evidence from Pixiv

　　　　　　　 (with Ginger Zhe Jin & Eungik Lee) 

発表言語 language：ENG

会場 venue：教授研究棟 03-G会議室  Room 03-G in Research Building

概要 abstract ：Using a comprehensive dataset of posts from a major platform for anime- and manga-style artwork, we study the impact of the launch of a prominent text-to-image generative AI. Focusing on the majority of incumbent creators who do not adopt AI as a primary tool, we show that the AI launch led to a significant decline in post uploads by illustrators, whereas comic artists were less affected, reflecting the need for tight stylistic alignment across sequential images in comics. We present empirical evidence for two underlying mechanisms. First, illustration posts experience a loss of viewer attention, measured by bookmarks, following the AI launch, which can significantly harm creators’ business models. Second, direct competition from AI-generated content plays an important role: illustrators working on intellectual properties (IPs, such as Pokémon) that are more heavily invaded by AI reduce their uploads disproportionately more. We further examine creators’ responses and show that illustrators with greater exposure to AI avoid using tags favored by AI-generated content after the AI launch and broaden the range of IPs they work on, consistent with a risk-hedging response to AI invasion.

高山 太輔 ( 京都大学 大学院農学研究科)

Taisuke Takayama( Graduate School of Agriculture, Kyoto University )

日時 date：2026年11月5日（木 Thurs） Google Calendar

時間 time：16:30-18:00

タイトル title：Land reform and long-term agricultural development: Evidence from post-World War II Japan 

発表言語 language：TBA

会場 venue：教授研究棟 03-G会議室  Room 03-G in Research Building

概要 abstract ：This study examines how granting land ownership affects long-term agricultural development through its interaction with tenancy reform. We focus on two major property rights reforms in Japan. The 1947 Land Reform forcefully redistributed farmland above a specified land ceiling from landlords to tenants, securing ownership but restricting transferability. The 1970 Tenancy Reform subsequently eliminated these ceilings and relaxed rental restrictions. To address endogeneity, we employ an instrumental variable approach based on the reform's land ceilings—using the pre-reform ratio of landholdings just above the ceiling to those just below—to exploit exogenous spatial variation in reform intensity. Combining contemporary farm-level data and community-level panel data, we find that the historical intensity of the land reform had a profound positive effect on long-term agricultural performance. By the year 2000, these secure-ownership areas achieved significantly larger farm sizes, higher agricultural revenues, and advanced crop diversification. We identify two primary mechanisms driving this development. First, stronger historical ownership security significantly promoted long-term farmland infrastructure investments. Second, once the 1970 reform unlocked tradability, communities with higher reform intensity experienced rapid farmland rental, land liquidity, and structural concentration. This study highlights that while secure ownership fosters long-term investment, tradability must be unlocked to drive dynamic structural transformations. 

今井 泰佑( 大阪大学 社会経済研究所)

Taisuke Imai( Institute of Social and Economic Research, The University of Osaka )

日時 date：2026年11月19日（木 Thurs） Google Calendar

時間 time：16:30-18:00

タイトル title：Wandering in the Garden of Forking Paths 

発表言語 language：JPN

会場 venue：教授研究棟 03-G会議室  Room 03-G in Research Building

概要 abstract ：The credibility of published scientific findings has become a central concern in empirical social science over the past decade. In response, a range of practices have been proposed and adopted to make empirical research more transparent and reproducible. Among them, preregistration and pre-analysis plans (hereafter jointly PAP) have gained widespread acceptance and are now mandated (or at least strongly encouraged) by many journals across a variety of fields. Yet important questions remain about how these practices should be implemented, how researchers perceive them, and how they are actually put into use. In this talk, I will present two projects examining several aspects of PAP in empirical social science. The first  investigates experimental economists' attitudes toward PAPs, their adoption, and perceived norms, drawing on survey evidence. The second examines the practical implementation of PAP, presenting findings from a recent large-scale experiment. These projects jointly highlight both researchers' engagement with PAP and the challenges of putting it into practice. 

野津 成希( 大阪大学 大学院国際公共政策研究科)

Naruki Notsu ( Osaka School of International Public Policy, University of Osaka )

日時 date：2026年11月26日（木 Thurs） Google Calendar

時間 time：16:30-18:00

タイトル title：TBA

発表言語 language：TBA

会場 venue：教授研究棟 03-G会議室  Room 03-G in Research Building

概要 abstract ：TBA

小笠原 浩太( 東京科学大学工学院)

Kota Ogasawara ( Department of Industrial Engineering and Economics, Institute of Science Tokyo )

日時 date：2026年12月10日（木 Thurs） Google Calendar

時間 time：16:30-18:00

タイトル title：TBA

発表言語 language：TBA

会場 venue：教授研究棟 03-G会議室  Room 03-G in Research Building

概要 abstract ：TBA