Oligopolistic Agreement and/or Superiority?: New Findings from New Methodologies and Data

The influential Scherer and Ross text (1990, p. 411) states that the main question in empirical industrial organization in the latter part of the twentieth century is Bains (1951) collusion or agreement hypothesis versus Demsetzs (1973) superior firm hypothesis. Prior to the Federal Trade Commission Line-of-Business (LOB) studies the contending schools were deadlocked, but these studies led to a win being declared for the superiority hypothesis by Scherer writing with seven other LOB researchers (1987). These studies found that the effect of concentration on profits disappeared when controlling for firm shares. As many economists agreed, merger policy shifted away from a focus on agreement to applying a unilateral effects (non-cooperative Nash) approach. We develop a nine year panel LOB data set for Korea. We perform three types of tests, all of which support both hypotheses, but which show that the agreement effect overwhelmingly dominates the superiority effect in pricing. First we examine a secondary implication of the superiority model: profit aggregation should imply that if share is negatively related to firm profits, so should concentration be negatively related to industry profits. Instead, we find that for those industries with a negative share relationship, the concentration profits relationship is positive and virtually identical to the relationship for the full sample in both within and between panel tests. Next we introduce a commonly cited model in the empirical literature. This model is cited to motivate the proposition that both share and concentration should have an effect on firm profits. However, authors who cite this model then typically use an ad hoc specification rather than estimating this as a structural model. We develop our structural model and define latent variables to distinguish between domestic and export price cost margins (PCMs) and to identify firm conjectures as they impact the domestic PCM. Demand elasticities are captured in non-linear industry fixed effects. We show that concentration plays an overwhelming role in determining firm PCMs, with firm share playing a far smaller role. We additionally exploit the structural characteristics of the model to deal with the possibility that deviations between marginal costs and average costs might be driving the results. For supporting evidence we construct a new latent variable identifying the domestic/export price ratio. We find a strong within relationship between concentration and the domestic/export price ratio, again firm shares play a weaker role. Finally, we discuss why our results differ from the FTC-LOB studies and provide evidence that would suggest that the FTC studies conclusions are biased due to the 1973 removal of price controls and energy crisis, the stagflation of the 1970s, and the use of national firm shares along with geographically weighted averages of concentration ratios.Industrial Organization,

A study of the causal relationship between IT governance inhibitors and its success in Korea enterprises

노트 : Proceedings of the 41st Hawaii International Conference on System Sciences - 2008 행사명 : 41st Hawaii International Conference on System Sc

Atopic Dermatitis-Like Skin Lesions Reduced by Topical Application and Intraperitoneal Injection of Hirsutenone in NC/Nga Mice

Atopic dermatitis (AD) is a common inflammatory skin disease. The increasing prevalence and severity of AD have prompted the developments of safer, more effective drugs. Although topical corticosteroids have been used as first line therapy for AD, their potential side effects limit their clinical applications. To investigate the effect of hirsutenone (HIR), a diarylheptanoid compound, on AD-like skin lesions and other factors related to immune response is the aim of this paper Th2-related cytokines (IL-4, IL-5, IL-13), eosinophil, IgE inflammatory factors (COX-2, iNOS) levels were reduced in blood, lymphocytes, and tissue after HIR treatment. These results suggest that HIR might be an effective treatment for AD

Functional analyses of heterotrimeric G protein Gα and Gβ subunits in Gibberella zeae

The homothallic ascomycete fungus Gibberella zeae (anamorph: Fusarium graminearum) is a major toxigenic plant pathogen that causes head blight disease on small-grain cereals. The fungus produces the mycotoxins deoxynivalenol (DON) and zearalenone (ZEA) in infected hosts, posing a threat to human and animal health. Despite its agricultural and toxicological importance, the molecular mechanisms underlying its growth, development and virulence remain largely unknown. To better understand such mechanisms, we studied the heterotrimeric G proteins of G. zeae, which are known to control crucial signalling pathways that regulate various cellular and developmental responses in fungi. Three putative Gα subunits, GzGPA1, GzGPA2 and GzGPA3, and one Gβ subunit, GzGPB1, were identified in the F. graminearum genome. Deletion of GzGPA1, a homologue of the Aspergillus nidulans Gα gene fadA, resulted in female sterility and enhanced DON and ZEA production, suggesting that GzGPA1 is required for normal sexual reproduction and repression of toxin biosynthesis. The production of DON and ZEA was also enhanced in the GzGPB1 mutant, suggesting that both Gα GzGPA1 and Gβ GzGPB1 negatively control mycotoxin production. Deletion of GzGPA2, which encodes a Gα protein similar to A. nidulans GanB, caused reduced pathogenicity and increased chitin accumulation in the cell wall, implying that GzGPA2 has multiple functions. Our study shows that G. zeae heterotrimeric G protein subunits can regulate vegetative growth, sexual development, toxin production and pathogenicity

Chapter7 The current situation of North Korean economy and the South-North Korea economic cooperation

サハリン石油・ガス開発プロジェクトと北海道経済の活性化 (4)ビジネス創造センターディスカッション・ペーパー・シリーズ14