Koichiro Iwamoto

The Run on Daily Foods and Goods after the 2011 Tohoku Earthquake: A Fact Finding Analysis Based on Homescan Data

Using high-frequency scan-based data on purchases by households compiled by a market research firm, this article examines changes in consumption patterns in the period of confusion immediately after the 2011 Tohoku earthquake. In particular, we focus on the panic buying of foods and daily necessities observed mainly in the Tokyo metropolitan area immediately after the unprecedented disaster. The results of our empirical analysis suggest that the sudden increase in daily expenditure due to panic buying was mainly due to a jump in the share of households that engaged in buying; on the other hand, increases in prices and the quantities that each household purchased were limited. Furthermore, based on regression analyses on items for which panic buying was clearly observed, we found that households that engaged in panic buying appear to have hoarded a wide range of commodities at random (i.e., they purchased rice, bread, noodles, and whatever they could lay their hands on).

Do the Rich Save More in Japan? Evidence Based on two Micro Data Sets for the 2000s

Using two household surveys for Japan, the Family and Lifestyle Survey (FLS) and the Family Income and Expenditure Survey (FIES), this paper investigates whether the saving rates of richer households (households with higher lifetime wealth) are higher than those of poorer households. The major difficulty in addressing this issue empirically is that a reliable proxy for lifetime wealth is rarely available. We therefore construct a number of proxies from the two surveys. While the estimated relationships are sensitive to the choice of proxy for lifetime wealth, the patterns observed for working age households in Japan are generally consistent with those reported for Western countries: we find significant positive correlations between saving rates and lifetime wealth when we use education and/or the type of occupation (job) as proxies, while the positive correlations disappear when we use consumption as an alternative proxy. We also try alternative proxies original to this study: lagged consumption, household assets, and/or purchase prices and find that the results with these instruments indicate marginally positive correlations between saving rates and lifetime wealth for working age households. We further find that the relationship between saving rates and lifetime wealth differs depending on the life stage of individual households. Older households with higher lifetime wealth appear to be dissaving to some extent, which is more or less consistent with the lifecycle model of consumption.

Match-Rigging in Professional Sumo: Elucidation of Incentive Structures and Empirical Analysis

Abstract: This article first develops a simple model to show that incentives for match-rigging in professional sumo differ depending on the rank to which a wrestler belongs. While incentives for matchrigging can arise for wrestlers in the top divisions (sekitori), few incentives arise for wrestlers-in-training (makushita and below). We then report the results of our empirical analysis, which show that match-rigging in the top divisions has declined in the post-Duggan and Levitt (2002) period, and that at the wrestler-in-training level there was no statistically detectable match-rigging during any period. We further find that match-rigging in professional sumo has stabilized at statistically undetectable levels following the mobile phone text message match-rigging scandal, and that on average the wrestlers selected for sanctions following the scandal were in fact those most involved in match-rigging.

Match-Rigging in Professional Sumo

Abstract:This article first develops a simple model to show that incentives for match-rigging in professional sumo differ depending on the rank to which a wrestler belongs. While incentives for matchrigging can arise for wrestlers in the top divisions (sekitori), few incentives arise for wrestlers-in-training (makushita and below). We then report the results of our empirical analysis, which show that match-rigging in the top divisions has declined in the post-Duggan and Levitt (2002) period, and that at the wrestler-in-training level there was no statistically detectable match-rigging during any period. We further find that match-rigging in professional sumo has stabilized at statistically undetectable levels following the mobile phone text message match-rigging scandal, and that on average the wrestlers selected for sanctions following the scandal were in fact those most involved in match-rigging.