Corporate diversification and performance: Evidence from Korea.

This dissertation examines a sample of firms from the 70 largest Korean conglomerates, or chaebols, in order to determine the motivation behind their diversification strategies and to identify the effects of diversification on economic performance. The first essay, "Government Revenue Maximization, External Capital and Corporate Diversification, " examines the argument that firms that have easy access to external capital, which is directly related to government subsidies in Korea, become over-diversified. The empirical analysis shows that firms with a high debt level are the most likely to pursue diversified expansion. Furthermore, this study shows that these firms have a tendency to decrease their diversification level when the government reduces business subsidies. The analysis conducted here is consistent with the argument that extensive and skewed subsidies lead industrial firms to accumulate considerable resources that are a springboard for excessive diversification.The second essay, entitled, "Chaebol Structure and Industry Productivity Growth in Korea, " focuses on the effects of corporate diversification on performance rather than any particular aim that lies behind diversification strategies. According to prevailing studies, the over-diversification of Korea's large business conglomerates was an important source of inefficiency, which resulted in an industrial structure that was particularly susceptible to the financial shocks of the 1990s. My empirical tests are consistent with this argument, as they show that industries with higher levels of chaebol diversification have lower levels of productivity and productivity growth. These findings are consistent with previous studies in other countries, which have found that diversification is negatively related to economic performance

An Exploratory Study of the Effects of Price Decreases on Online Product Reviews: Focusing on Amazon’s Kindle 2

As online shopping proliferates, online product reviews (OPRs) play a crucial role in online consumers’ purchasing decisions. Although prior research on the effects of price changes on consumer reactions has provided insightful implications, little is known about the impact of price changes on the characteristics of OPRs. With the growing importance of OPRs as a key social recommendation system for potential consumers’ decision-making, it is important to understand the dynamics of OPRs around price changes. We select the Kindle 2 from Amazon.com as our focal product and conduct an exploratory case study. By analyzing 6,714 reviews on the Kindle 2, we examine how consumers respond to price decreases using OPRs. The results show that all four characteristics of OPRs (star-rating, review depth, positive emotion, and negative emotion) are significantly influenced by price decreases. Moreover, we found that the impacts of price decreases on OPRs’ characteristics are different between the first and the second attempts at price reduction. Interestingly, the number of reviews per day significantly soars immediately after the first price decrease, while there is no significant change in the number of reviews after the second price cut. We conclude the paper with a discussion of our findings

An Analysis of the Interaction of Trade and Foreign Direct Investment between South Korea and India

This paper is the revised version of the paper presented at the 21st Seoul Journal of Economics International Symposium at Seoul National University on September 3, 2013.This paper investigates the interaction of foreign direct investment (FDI) and trade between S. Korea and India from 1983 to 2012. To examine the relationship between trade and FDI, we established multivariate estimations for trade and FDI, including Gross National Income and effective exchange rate. We applied impulse response analysis using the Vector Error Correction Model to determine the effect of a shock emanating from an endogenous variable on other variables. One finding is that a unidirectional link exists between trade and FDI, but not vice versa. The export of S. Korea to India positively affects the growth of the outward FDI of S. Korea into India. This finding indicated that the relationship between trade and FDI of S. Korea to India is unidirectional. Both trade and FDI also do not affect either the income of the two countries or their effective exchange rate. The main reason for this result is that the amount of FDI and/or trade is considerably small to generate any dynamic spillover effect

The Grind for Good Data: Understanding ML Practitioners' Struggles and Aspirations in Making Good Data

We thought data to be simply given, but reality tells otherwise; it is costly, situation-dependent, and muddled with dilemmas, constantly requiring human intervention. The ML community's focus on quality data is increasing in the same vein, as good data is vital for successful ML systems. Nonetheless, few works have investigated the dataset builders and the specifics of what they do and struggle to make good data. In this study, through semi-structured interviews with 19 ML experts, we present what humans actually do and consider in each step of the data construction pipeline. We further organize their struggles under three themes: 1) trade-offs from real-world constraints; 2) harmonizing assorted data workers for consistency; 3) the necessity of human intuition and tacit knowledge for processing data. Finally, we discuss why such struggles are inevitable for good data and what practitioners aspire, toward providing systematic support for data works

A Synergistic Anti-Diabetic Effect by Ginsenosides Rb1 and Rg3 through Adipogenic and Insulin Signaling Pathways in 3T3-L1 Cells

Although ginsenosides Rb1 and Rg3 have been identified as the significant ginsenosides found in red ginseng that confer anti-diabetic actions, it is unclear whether insulin-sensitizing effects are mediated by the individual compounds or by their combination. To determine the effect of ginsenosides Rb1 and Rg3 on adipocyte differentiation, 3T3-L1 preadipocytes were induced to differentiate the standard hormonal inducers in the absence or presence of ginsenosides Rb1 or Rg3. Additionally, we determined the effects of Rb1, Rg3, or their combination on the expression of genes related to adipocyte differentiation, adipogenic transcription factors, and the insulin signaling pathway in 3T3-L1 cells using semi-quantitative RT-PCR. Rb1 significantly increased the expression of CEBP alpha, PPAR gamma, and aP2 mRNAs. However, Rg3 exerted its maximal stimulatory effect on these genes at 1 mu M concentration, while a high concentration (50 mu M) showed inhibitory effects. Similarly, treatment with Rb1 and Rg3 (1 mu M) increased the expression of IRS-1, Akt, PI3K, GLUT4, and adiponectin. Importantly, co-treatment of Rb1 and Rg3 (9:1) induced the maximal expression levels of these mRNAs. Our data indicate that the anti-diabetic activity of red ginseng is, in part, mediated by synergistic actions of Rb1 and Rg3, further supporting the significance of minor Rg3

Spatially resolved penetration depth measurements and vortex manipulation in the ferromagnetic superconductor ErNi2B2C

We present a local probe study of the magnetic superconductor, ErNi$_2$B$_2$C, using magnetic force microscopy at sub-Kelvin temperatures. ErNi$_2$B$_2$C is an ideal system to explore the effects of concomitant superconductivity and ferromagnetism. At 500 mK, far below the transition to a weakly ferromagnetic state, we directly observe a structured magnetic background on the micrometer scale. We determine spatially resolved absolute values of the magnetic penetration depth $\lambda$ and study its temperature dependence as the system undergoes magnetic phase transitions from paramagnetic to antiferromagnetic, and to weak ferromagnetic, all within the superconducting regime. In addition, we estimate the absolute pinning force of Abrikosov vortices, which shows a position- and temperature dependence as well, and discuss the possibility of the purported spontaneous vortex formation