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Akihiko Noda

Publications and source records attributed to Akihiko Noda.

18 recordsLinked to original sources
arXiv2026

Wartime Controls, Political Connections, and the Pricing of Zaibatsu Rents in Japan, 1930-1943

This paper examines how wartime economic controls shaped stock-price formation in Japan from 1930 to 1943. We develop a four-portfolio asset-pricing model in which zaibatsu affiliation affects expected payoffs and the translation of valuations into economic scale through lower financing wedges. We then construct daily capitalization-weighted indices and four benchmark portfolios based on a two-by-two sort by zaibatsu affiliation and military orientation. Using a CAPM-AR(p)-SV event-study framework that allows for serial correlation and stochastic volatility, we show that the model rationalizes capitalization concentration, segmented abnormal returns, delayed cumulative adjustment, regime-risk insulation of zaibatsu portfolios, and zaibatsu-concentrated responses to embedded-rent or group-continuation shocks. The evidence is consistent not with a collapse of semi-strong efficiency, but with institutionally contingent efficiency: stock prices continued to respond to news while capitalizing uneven access to credit, materials, and procurement.

econ.GN↗
arXiv2026

Finite-Sample Properties of Model Specification Tests for Multivariate Dynamic Regression Models

We propose a new model specification test for multiple-equation systems with cross-equation error and dynamic regressor--error dependences. Conventional tests often rely on exogeneity conditions strong enough to ensure consistency of the OLS estimator. These exogeneity conditions are violated when regressors and errors are dynamically dependent, rendering conventional model specification tests invalid. To address these limitations, we clarify the relationship among alternative exogeneity conditions, characterize the consistency of competing multiple-equation estimators, and propose a generalized Durbin estimator for multiple-equation systems with an intercept, cross-equation error and regressor--error dependences. We show that our estimator remains consistent under the weakest exogeneity condition. We then derive its asymptotic distribution and construct Wald tests. Our Monte Carlo experiments confirm that the bootstrap-based Wald test substantially improves finite-sample size control. An application of the bootstrap-based Wald test to the Fama--French multifactor models leaves the null hypothesis unrejected in cases where competing FGLS-based tests reject it.

econ.EM↗
arXiv2024

Time Instability of the Fama-French Multifactor Models: An International Evidence

This paper investigates the time-varying structure of Fama and French's (1993; 2015) multi-factor models using Fama and MacBeth's (1973) two-step estimation based on the rolling window method. In particular, we employ the generalized GRS statistics proposed by Kamstra and Shi (2024) to examine whether the validity of the risk factors (or factor redundancy) in the FF3 and FF5 models remains stable over time, and investigate whether the manner of portfolio sorting affects the time stability of the validity of the risk factors. In addition, we examine whether the similar results are obtained even when we use different datasets by country and region. First, we find that the effectiveness of factors in the FF3 and FF5 models is not stable over time in all countries. Second, the effectiveness of factors is also affected by the manner of portfolio sorting. Third, the validity of the FF3, FF5, and their nested models do not remain stable over time except for Japan. This suggests that the efficient market hypothesis is supported in the Japanese stock market. Finally, the factor redundancy varies over time and is affected by the manner of portfolio sorting mainly in the U.S. and Europe.

q-fin.ST↗
arXiv2024

Measuring the Time-Varying Market Efficiency in the Prewar and Wartime Japanese Stock Market, 1924-1943

This study explores the time-varying structure of market efficiency in the prewar and wartime Japanese stock market using a new market capitalization-weighted stock price index, the equity performance index. We examine whether the adaptive market hypothesis (AMH) is supported in that era. First, we find that the degree of market efficiency in the prewar and wartime Japanese stock market varies over time and with major historical events. This implies that the AMH is supported in this market. Second, we find that the variation in market efficiency observed in this study is significantly different from that in previous studies because of whether the price index is capitalization weighted. Finally, as government intervention in the market intensified throughout the 1930s, market efficiency declined as the war risk premium rose, especially from the time when the Pacific War became inevitable.

q-fin.ST↗
arXiv2024

On the Time-Varying Structure of the Arbitrage Pricing Theory using the Japanese Sector Indices

This paper is the first study to examine the time instability of the APT in the Japanese stock market. In particular, we measure how changes in each risk factor affect the stock risk premiums to investigate the validity of the APT over time, applying the rolling window method to Fama and MacBeth's (1973) two-step regression and Kamstra and Shi's (2023) generalized GRS test. We summarize our empirical results as follows: (1) the changes in monetary policy by major central banks greatly affect the validity of the APT in Japan, and (2) the time-varying estimates of the risk premiums for each factor are also unstable over time, and they are affected by the business cycle and economic crises. Therefore, we conclude that the validity of the APT as an appropriate model to explain the Japanese sector index is not stable over time.

q-fin.ST↗
arXiv2021

Examining the Dynamic Asset Market Linkages under the COVID-19 Global Pandemic

This study examines the dynamic asset market linkages under the COVID-19 global pandemic based on market efficiency, in the sense of Fama (1970). Particularly, we estimate the joint degree of market efficiency by applying Ito et al.'s (2014; 2017) Generalized Least Squares-based time-varying vector autoregression model. The empirical results show that (1) the joint degree of market efficiency changes widely over time, as shown in Lo's (2004) adaptive market hypothesis, (2) the COVID-19 pandemic may eliminate arbitrage and improve market efficiency through enhanced linkages between the asset markets; and (3) the market efficiency has continued to decline due to the Bitcoin bubble that emerged at the end of 2020.

q-fin.ST↗
arXiv2021

Evaluating the Financial Market Function in Prewar Japan using a Time-Varying Parameter Model

This paper explores when the financial market lost the price formation function in prewar Japan in the sense of Fama's (1970) semi-strong form market efficiency using a new dataset. We particularly focus on the relationship between the prewar Japanese financial market and several government policy interventions to explore whether the semi-strong form market efficiency evolves over time. To capture the long-run impact of government policy interventions against the markets, we measure the time-varying joint degree of market efficiency and the time-varying impulse responses based on Ito et al.'s (2014; 2017) generalized least squares-based time-varying vector autoregressive model. The empirical results reveal that (1) the joint degree of market efficiency in the prewar Japanese financial market fluctuated over time because of external events such as policy changes and wars, (2) the semi-strong form EMH is almost supported in the prewar Japanese financial market, (3) Lo's (2004) adaptive market hypothesis is supported in the prewar Japanese financial market even if we consider that the public information affects the financial markets, and (4) the prewar Japanese financial markets lost the price formation function in 1932 and that was a turning point in the market.

q-fin.ST↗
arXiv2020

On the Evolution of Cryptocurrency Market Efficiency

This study examines whether the efficiency of cryptocurrency markets (Bitcoin and Ethereum) evolve over time based on Lo's (2004) adaptive market hypothesis (AMH). In particular, we measure the degree of market efficiency using a generalized least squares-based time-varying model that does not depend on sample size, unlike previous studies that used conventional methods. The empirical results show that (1) the degree of market efficiency varies with time in the markets, (2) Bitcoin's market efficiency level is higher than that of Ethereum over most periods, and (3) a market with high market liquidity has been evolving. We conclude that the results support the AMH for the most established cryptocurrency market.

q-fin.ST↗
arXiv2018

Discretion versus Policy Rules in Futures Markets: A Case of the Osaka-Dojima Rice Exchange, 1914-1939

We investigate the relationship between market efficiency of rice futures transaction in Osaka and the Japanese government intervention in rice distributions by directly buying and selling rice during the interwar period, from the middle 1910s to 1939, considering the context of "discretion versus rules." We use a time-varying VAR model to compare market efficiency and the government's actions over time. We found the two facts by featuring the time-varying nature of the market efficiency. First, the intervention with discretionary power disrupted the rice market and reduced market efficiency in the exchange. Second, the market efficiency improved in accordance with reduction in the government's discretionary power to operate the rice policy. When the government obtained the discretionary power to operate the policy regarding commodity market, the market efficiency often reduced. Conversely, even if the government implemented a large-scale intervention, the market efficiency improved when the government chose a systematic rule-like behavior following the law.

q-fin.ST↗
arXiv2017

An Alternative Estimation Method of a Time-Varying Parameter Model

A non-Bayesian, regression-based or generalized least squares (GLS)-based approach is formally proposed to estimate a class of time-varying AR parameter models. This approach has partly been used by Ito et al. (2014, 2016a,b), and is proven to be efficient because, unlike conventional methods, it does not require Kalman filtering and smoothing procedures, but yields a smoothed estimate that is identical to the Kalman-smoothed estimate. Unlike the maximum likelihood estimator, the possibility of the pile-up problem is negligible. In addition, this approach enables us to deal with stochastic volatility models, models with a time-dependent variance-covariance matrix, and models with non-Gaussian errors that allow us to deal with abrupt changes or structural breaks in time-varying parameters.

stat.ME↗
arXiv2017

Market Integration in the Prewar Japanese Rice Markets

This paper examines the integration process of the Japanese major rice markets (Tokyo and Osaka) from 1881 to 1932. Using a non-Bayesian time-varying vector error correction model, we argue that the process strongly depended on the government's policy on the network system of the telegram and telephone; rice traders with an intention to use modern communication tools were usually affected by the changes in policy. We find that (i) the Japanese rice markets had been integrated in the 1910s; (ii) increasing use of telegraphs had accelerated rice market integration from the Meiji period in Japan; and (iii) local telephone system, which reduced the time spent by urban users sending and receiving telegrams, promoted market integration.

q-fin.GN↗
arXiv2017

The Futures Premium and Rice Market Efficiency in Prewar Japan

This paper studies the interrelation between spot and futures prices in the two major rice markets in prewar Japan from the perspective of market efficiency. Applying a non-Bayesian time-varying model approach to the fundamental equation for spot returns and the futures premium, we detect when efficiency reductions in the two major rice markets occurred. We also examine how government interventions affected the rice markets in Japan, which colonized Taiwan and Korea before World War II, and argue that the function of rice futures markets crucially depended on the differences in rice spot market's structure. The increased volume of imported rice of a different variety from domestic rice first disrupted the rice futures. Then, government intervention in the rice futures markets failed to improve the disruption. Changes in colonial rice cropping successfully improved the disruption, and colonial rice was promoted to unify the different varieties of inland and colonial rice.

q-fin.ST↗
arXiv2017

Market Efficiency and Government Interventions in Prewar Japanese Rice Futures Markets

This study analyzes how colonial rice trade in prewar Japan affected its rice market, considering several government interventions in the two rice futures exchanges in Tokyo and Osaka. We explore the interventions in the futures markets using two procedures. First, we measure the joint degree of efficiency in the markets using a time-varying vector autoregression model. Second, we examine many historical events that possibly affected the markets and focus on one event at a time. The degree varies over time within our sample period (1881-1932). The observation, together with historical analysis, leads to the following conclusions. (1) The two major markets in Tokyo and Osaka were nearly efficient. (2) Government interventions involving the delivery of imported rice from Taiwan and Korea often reduced futures market efficiency. Finally, (3) this relationship continued as long as the quality difference between imported and domestic rice existed. The government interventions that promoted domestic distributions of the colonial goods resulted in confusion in the commodity markets, and decreased efficiency of the markets in the metropole.

q-fin.GN↗
arXiv2016

Time-Varying Comovement of Foreign Exchange Markets

A time-varying cointegration model for foreign exchange rates is presented. Unlike previous studies, we allow the loading matrix in the vector error correction (VEC) model to be varying over time. Because the loading matrix in the VEC model is associated with the speed at which deviations from the long-run relationship disappear, we propose a new degree of market comovement\ based on the time-varying loading matrix to measure the strength or robustness of the long-run relationship over time. Since exchange rates are determined by macrovariables, cointegration among exchange rates implies those macroeconomic variables share common stochastic trends. Therefore, the proposed degree measures the degree of market comovement. Our main finding is that the market comovement has become stronger over the past quarter century, but the rate at which market comovement strengthens is decreasing with two major turning points: one in 1995 and the other one in 2008.

q-fin.ST↗
arXiv2016

A Test of the Adaptive Market Hypothesis using a Time-Varying AR Model in Japan

This study examines the adaptive market hypothesis (AMH) in Japanese stock markets (TOPIX and TSE2). In particular, we measure the degree of market efficiency by using a time-varying model approach. The empirical results show that (1) the degree of market efficiency changes over time in the two markets, (2) the level of market efficiency of the TSE2 is lower than that of the TOPIX in most periods, and (3) the market efficiency of the TOPIX has evolved, but that of the TSE2 has not. We conclude that the results support the AMH for the more qualified stock market in Japan.

q-fin.ST↗
arXiv2015

The Evolution of Stock Market Efficiency in the US: A Non-Bayesian Time-Varying Model Approach

A non-Bayesian time-varying model is developed by introducing the concept of the degree of market efficiency that varies over time. This model may be seen as a reflection of the idea that continuous technological progress alters the trading environment over time. With new methodologies and a new measure of the degree of market efficiency, we examine whether the US stock market evolves over time. In particular, a time-varying autoregressive (TV-AR) model is employed. Our main findings are: (i) the US stock market has evolved over time and the degree of market efficiency has cyclical fluctuations with a considerably long periodicity, from 30 to 40 years; and (ii) the US stock market has been efficient with the exception of four times in our sample period: during the long-recession of 1873-1879; the recession of 1902-1904; the New Deal era; and the recession of 1957-1958 and soon after it. It is then shown that our results are partly consistent with the view of behavioral finance.

q-fin.ST↗
arXiv2014

International Stock Market Efficiency: A Non-Bayesian Time-Varying Model Approach

This paper develops a non-Bayesian methodology to analyze the time-varying structure of international linkages and market efficiency in G7 countries. We consider a non-Bayesian time-varying vector autoregressive (TV-VAR) model, and apply it to estimate the joint degree of market efficiency in the sense of Fama (1970, 1991). Our empirical results provide a new perspective that the international linkages and market efficiency change over time and that their behaviors correspond well to historical events of the international financial system.

q-fin.ST↗