東北大学
現代経済学研究会
この研究会について:
 2006年度より、東北大学に在籍する経済学研究者有志が集まって定期的に研究会を開催することになりました。本研究会では国際的学術雑誌への投稿を精力的に行っている第一線の研究者に研究発表をお願いしています。参加資格は特に設けませんので、報告論題に関心のある方は奮ってご参加ください。学内の方はもちろん、学外の方もご参加いただけます。

 開催予定はあくまで暫定であり、日時が変更されたりキャンセルされる場合があります。ご注意ください。

アクセス情報:
 第401演習室は、経済学部研究棟ではなく、文科系総合研究棟(教育学研究科が入居している建物)の4階にあるのでご注意ください。
 経済学研究科へのアクセスと川内キャンパス内の建物の配置についてはこの地図をご参照ください(地図中のC16が経済学部研究棟、C14が文科系総合研究棟です)。

共催情報:
 今年度の研究会は全てサービス・データ科学研究センターワークショップとの共催です。
 サービス・データ科学研究センターについてはこのサイトをご参照ください。









セミナー幹事: 松前 龍宜
matsumae@tohoku.ac.jp

10月18日(木) 16:20-17:50 第401演習室(文科系総合研究棟4階)
応用統計計量ワークショップとの共催                  

平野智裕 氏 (東京大学)

The Wobbly Economy

Abstract: This paper explores the standard life-cycle model, showing that (a) under not implausible conditions, there may be an infinity of rational expectation equilibria; this may occur even when under myopic expectations, there is a unique dynamic path; (b) nonetheless, one can provide interesting characterizations of economic dynamics; (c) government policy can affect the equilibrium path, and indeed appropriately chosen government policy rules can ensure that the rational expectations equilibrium is unique and can improve welfare. Moreover, we show that productivity increase may generate fragile economic booms followed by stagnation trap. Appropriate government policy can prevent an economy from falling into stagnation trap and can improve welfare.



2018年10月25日(木) 16:20-17:50 大会議室(経済学部研究棟4階)
Language: English, 応用統計計量ワークショップとの共催 
いつもと会場が異なります.

Christina Atanasova 氏 (Simon Fraser University)

Title: Firm Diversification Affects Liquidity Management: The Role of Lines of Credit (abstract)

I examine whether organizational form matter for corporate liquidity, focusing on the effect of business diversification on firms' choice between bank lines of credit and cash holdings. I find that diversified firms have relied on bank lines of credit more than their focused counterparts, as they have increased their liquidity in the last two decades. I test several theoretical explanations for this finding. First, I find no evidence that diversified firms with lower aggregate risk (beta) have a higher probability of obtaining credit lines or use higher amounts of revolving credit than the higher beta firms. However, high idiosyncratic risk of borrowers hinders their access to credit lines. This effect is larger for smaller and for non-investment grade firms. My results are consistent with the monitored liquidity insurance hypothesis, where diversified firms with lower liquidity risk and hedging demand use more bank lines of credit.


2018年11月22日(木) 16:30-18:00 第21演習室(文科系総合研究棟10階)
いつもと会場・時間が異なります.

十河丈晴 氏 (大阪経済大学)

Title: Costly Entry and the Optimality of Asymmetric Auction Designs (abstract)

We investigate optimal auction mechanisms when bidders base costly entry decisions on their valuations, and payments depend on both the bids and asset payoffs generated by the winning bidder. We show the optimal mechanism can feature asymmetry, where the seller sets differential reserve prices so that bidders enter with strictly positive but different (ex-ante) probabilities, even when bidders are ex-ante identical. The optimality of asymmetric mechanisms extends to cash auctions when there is sufficient valuation uncertainty relative to entry costs. When bidders pay with a fixed royalty rate plus cash, the optimal degree of asymmetry rises with the royalty rate.


2018年12月20日(木) 16:20-17:50 第401演習室(文科系総合研究棟4階)
Language: English, 応用統計計量ワークショップとの共催

Zhenlin Yang 氏 (Singapore Management University)

Title: TBA (abstract)

TBA


2019年1月24日(木) 16:20-17:50 大会議室(経済学部研究棟4階)
いつもと会場が異なります.

笠原博幸 氏 (University of British Columbia)

Title: TBA (abstract)

TBA


2019年1月31日(木) 16:20-17:50 第401演習室(文科系総合研究棟4階)

坂本陽子 氏 (University of Wisconsin-Madison)

Title: TBA (abstract)

TBA


2019年2月14日(木) 16:20-17:50 第21演習室(文科系総合研究棟10階)
いつもと会場が異なります.

西出勝正 氏 (一橋大学)

Title: TBA (abstract)

TBA



これまでの研究会:

2018年4月19日(木) 16:20-18:20 第401演習室(文科系総合研究棟4階)

鈴木通雄 氏 (東北大学)

Title: Decomposition of Aggregate Productivity Growth with Unobserved Heterogeneity (abstract)

Aggregate productivity growth and the role of input reallocation have been hotly debated. Yet, it has received little attention as to how the measurement of reallocation relies on the commonly-made assumption that a production technology is uniform within an industry. To quantify the effects of unobserved heterogeneity in production technology, we estimate a random-coefficient Cobb-Douglas production function. We identify plant type from the distribution of the intermediate inputs to sales ratio using the first order condition without permanent distortions in intermediate input markets. The empirical analysis uses plant-level data from the Census of Manufacture. We find that accounting for unobserved heterogeneity lowers the volatility of technical efficiency and reallocation contributions. For knitted garments industry that features large dispersion in the intermediate input share, the average growth rate of the reallocation component over the 5-year period after the bubble burst in Japan is -0.5% with heterogeneity, while it is 0.4% without heterogeneity.

湯田道生 氏 (東北大学)

Title: Medical Assistance System and Outpatient Health Care Utilization: Evidence from Japan (abstract)

The medical assistance (MA) system in Japan provides medical care services to public assistance beneficiaries without any financial burden, but it also could potentially increase the medical expenditure due to the two major inefficiencies: moral hazard and supplier-induced demand. In this study, nationally representative sets of medical claim data are used to examine how assignment to the MA system affects the utilization of outpatient health care. Empirical results obtained using a dummy endogenous variable model to control for non-random MA assignment, which is subject to means testing by the local government, shows that MA assignment significantly increases medical expenditure. Its arc elasticity ranges from -0.171 to -0.160, which is comparable to the RAND Health Insurance Experiment. In addition, after excluding fatal patients, the elasticity increases to -0.250, which exceeds that obtained in recent empirical studies of low-income populations. In addition, the elasticities for new MA patients are significantly larger than those for continuing patients and that MA clinic patients are particularly price-sensitive.


2018年4月26日(木) 16:30-18:00 第401演習室(文科系総合研究棟4階)
Language: English, いつもと時間が異なります。

Ian Coxhead 氏 (University of Wisconsin-Madison)

Title: Persistent privilege? Institutional education achievement gaps in Vietnam (abstract)

In an earlier paper examining Vietnam’s early economic transition, we documented a large educational achievement gap in favor of children from families with members employed by government or state enterprises. In this paper, we ask what has happened to that gap in the subsequent decade, as Vietnam’s private-sector economy has boomed and state corporations have contracted in relative terms. We find that despite these trends, high school and college enrollment by children of households that lack connections to state-sector employment continue to lag those that do, and in fact the gap has become appreciably wider. Though “connections” are not the only basis for differences in schooling decisions, they are a major cause of slow and unequal progress in educational attainment, a problem with consequences for intergenerational inequality and long-run growth.


2018年5月11日(金) 16:20-17:50 第401演習室(文科系総合研究棟4階)
いつもと曜日が異なります。

八木橋毅司 氏 (Old Dominion University)

Title: Intertemporal Elasticity of Substitution with Leisure Margin (abstract)

This paper investigates whether leisure time definitions matter in the estimation of the intertemporal elasticity of substitution of consumption (IES) by using a utility specification that allows interaction between consumption and leisure time. We find that the IES estimated using a narrowly defined leisure measure that excludes quasi-leisure activities is larger than that estimated using nonmarket time. The discrepancy is largely driven by the substitution of consumption and several leisure components over the lifecycle. This finding is robust in alternative specifications and holds well for subsamples of higher socioeconomic status. Our results demonstrate the inseparable nature of consumption and time allocation.


2018年5月17日(木) 16:20-17:50 第401演習室(文科系総合研究棟4階)

山田知明 氏 (明治大学)

Title: The Effects of Monetary Policy Shocks on Inequality in Japan (abstract)

The impacts of monetary easing on inequality have been attracting increasing attention recently. In this paper, we use the micro-level data on Japanese households to study the distributional effects of monetary policy. We construct quarterly series of income and consumption inequality measures from 1981 to 2008, and estimate their response to a monetary policy shock. We find that monetary policy shocks do not have a statistically significant impact on inequality across Japanese households in a stable manner. When considering inequality across households whose head is employed, we find evidence that, before the 2000s, an expansionary monetary policy shock increased income inequality through a rise in earnings inequality. Such procyclical responses are, however, scarcely observed when the current data are included in the sample period, or when earnings inequality across all households is considered. We also find that transmission of income inequality to consumption inequality is minor, including during the period when procyclicality of income inequality was pronounced. Using a two-sector dynamic general equilibrium model with attached labor inputs, we show that labor market flexibility is central to the dynamics of income inequality after monetary policy shocks. We also use the micro-level data on households' balance sheets and show that distributions of households' financial assets and liabilities do not play a significant role in the distributional effects of monetary policy.


2018年5月24日(木) 16:20-17:50 第401演習室(文科系総合研究棟4階)

小西秀樹 氏 (早稲田大学)

Title: How Redistributive are the Hidden Welfare States?: Private Social Expenditure and Redistribution in OECD countries (abstract)

The modern welfare states provide social protection services not only directly from the public sector but also from the private sector, e.g., by mandating employment-based provisions and giving tax breaks for voluntary transactions for social purposes. This paper incorporates such private social expenditures and estimates the redistributive impacts of social protection systems in OECD countries, using a dynamic panel model. It is found that the redistributive impact decreases as the system relies more on the private sector, some countries have no statistically significant redistributive impacts, and the OECD countries have strengthened redistribution thought social policy on average after 2000. It is also discussed how the estimation results depend on the choice of the income inequality index to regress.


2018年6月7日(木) 16:20-17:50 第401演習室(文科系総合研究棟4階)

白井大地 氏 (東北学院大学)

Title: Debt-Ridden Borrowers and Economic Slowdown (abstract)

Economic growth slows for an extended period after a financial crisis. We construct a model in which a one-time buildup of debt can depress the economy persistently, even when there is no financial technology shock. We consider the debt dynamics of firms under endogenous borrowing constraints, with lenders having an option to forgive defaulting borrowers. A firm is referred to as debt-ridden when it owes maximum debt and pays all income in each period as an interest payment. In the deterministic case, a debt-ridden firm continues inefficient production permanently. Further, if the initial debt exceeds a certain threshold, the firm intentionally chooses to increase borrowing and, thus, to become debt-ridden. The emergence of a substantial number of debt-ridden firms lowers economic growth persistently. A debt restructuring policy or the relief of debt-ridden borrowers from excessive debt may be able to restore their efficiency and economic growth.


2018年6月21日(木) 16:20-17:50 第401演習室(文科系総合研究棟4階)

島根哲哉 氏 (東京工業大学)

Title: Location Choice of Carsharing Stations: an Empirical Study (abstract)

Carsharing is a car rental system for short period use. The registered users rent cars from carsharing stations located very near their living spaces. We analyze the carsharing company's strategies of the location choice of their carsharing stations, then investigate the market structure of carsharing service. We segment the market by spatial grid, then model the location choice of carsharing stations as an entry game in each segmented space. We estimate the structural parameters of the carsharing company's payoff functions, using reduced form of the competitor's strategy estimated by nonparametric method. We found that the carsharing company's decisions are depend the activity of their parent company.


2018年6月28日(木) 16:20-17:50 第401演習室(文科系総合研究棟4階)

松村敏弘 氏 (東京大学)

Title: Firms' Costs, Profits, Entries, and Innovation under Optimal Privatization Policy (abstract)

We investigate how cost conditions of private firms affect optimal privatization policy and private firms' profits. We find that the optimal degree of privatization is decreasing with the costs of private firms unless the public firm is fully privatized in equilibrium. A cost reduction in a private firm increases the degree of privatization and benefits for all private firms. Therefore, each private firm's profit is increasing with its rival private firms' costs, which is in contrast to the result when the degree of privatization is given exogenously. This interesting property yields two important results. The profit of each private firm can increase with the number of private firms, and the positive externality of innovation accelerates private firms' R&D.


2018年7月5日(木) 16:20-17:50 第401演習室(文科系総合研究棟4階)

釜賀浩平 氏 (上智大学)

Title: An axiomatization of the mixed utilitarian-maximin social welfare orderings (abstract)

We axiomatize the class of mixed utilitarian-maximin social welfare orderings. These orderings are convex combinations of utilitarianism and the maximin rule. Our first step is to show that the conjunction of the weak Suppes-Sen principle, the Pigou-Dalton transfer principle, the composite transfer principle, and continuity is equivalent to the existence of a continuous and monotone ordering of pairs of average and minimum utilities that can be used to rank utility vectors. Using this observation, the main result of the paper establishes that the utilitarian-maximin social welfare orderings are characterized by adding the axiom of cardinal full comparability. In addition, we examine the consequences of replacing cardinal full comparability with ratioscale full comparability and translation-scale full comparability, respectively. We also discuss the classes of normative inequality measures corresponding to our social welfare orderings.


2018年7月19日(木) 16:20-17:50 第401演習室(文科系総合研究棟4階)
Language: English, 応用統計計量ワークショップとの共催

YoungJin Choi 氏 (Temple University)

Title: U.S. Quantitative easing and exchange rate regime (abstract)

This paper explores the international spillover effects of the U.S. quantitative easing in the dynamic stochastic general equilibrium (DSGE) model that incorporates asset market segmentation, managed exchange rate regime, sterilized interventions and capital controls in a small open economy. The same DSGE framework enables me to compare the international transmissions of the conventional vs unconventional monetary policy and evaluate optimal monetary policy based on welfare implications of alternative exchange rate regime and capital account liberalization. I found that the long-term bond yield under managed exchange rate regimes are more affected by the U.S. quantitative easing than under the flexible exchange rate regime. The liberalized capital account and currency regime mitigate the costs of sterilization and achieve to better stabilize the global financial shocks.


2018年7月26日(木) 16:20-17:50 第401演習室(文科系総合研究棟4階)
応用統計計量ワークショップとの共催

會田剛史 氏 (アジア経済研究所)

Title: Spatial vs. Social Network Effects in Risk Sharing (abstract)

Employing spatial panel econometric models, this study extends the conventional empirical test of the full risk-sharing hypothesis to incorporate spatial and social network effects, and quantifies the diffusion of income shocks in each network. Estimation results based on household survey data in Southern Sri Lanka show that consumption smoothing performs better in spatial networks than in social ones, because income shocks defuse more effectively among neighboring households. This study also shows the limitations of the conventional test when it is considered a special case of a spatial econometric model.


2018年8月2日(木) 16:20-17:50 第401演習室(文科系総合研究棟4階)

高橋修平 氏 (京都大学)

Title: Does State-Dependent Wage Setting Generate Multiple Equilibria? (abstract)

Does wage setting show strategic complementarity and produce multiple equilibria? This study constructs a discrete-time New Keynesian model in which households choose when to change their wage subject to a fixed wage-setting cost. I analyze a steady-state equilibrium of the state-dependent wage-setting model both analytically and numerically. I find that for reasonable parameter values, complementarity in wage setting is weak and multiple equilibria are unlikely to exist at the steady state. This result is robust to introducing imperfect insurance for consumption.


2018年10月4日(木) 16:20-17:50 第401演習室(文科系総合研究棟4階)
応用統計計量ワークショップとの共催

植松良公 氏 (University of Southern California)

Title: The SOFAR Framework and Estimating Weak Factor Models (abstract)

Many modern big data applications feature large scale in both numbers of responses and predictors. Better statistical efficiency and scientific insights can be enabled by understanding the large-scale response-predictor association network structures via layers of sparse latent factors ranked by importance. Yet sparsity and orthogonality have been two largely incompatible goals. To accommodate both features, in this presentation we first suggest the method of sparse orthogonal factor regression (SOFAR) via the sparse singular value decomposition with orthogonality constrained optimization to learn the underlying association networks, with broad applications to both unsupervised and supervised learning tasks such as biclustering with sparse singular value decomposition, sparse principal component analysis, sparse factor analysis, and spare vector autoregression analysis. Exploiting the framework of convexity-assisted nonconvex optimization, we derive nonasymptotic error bounds for the suggested procedure characterizing the theoretical advantages. The statistical guarantees are powered by an efficient SOFAR algorithm with convergence property. Next, we propose a consistent estimation method for the approximate factor model of Chamberlain and Rothschild (1983, Econometrica), known recently as weak factor models, by extending the SOFAR methodology. In our experiment, the performance of the new estimator dominates that of the principal component estimators in terms of mean absolute loss, and its superiority gets larger as the factor components become weaker. We apply our method to analyse S&P500 firm security monthly returns, and the results show that the largest eigenvalue grows proportional to the number of the firms, whilst the second and third much less slowly diverge.




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