Market Structure and International Trade: Business Groups in East Asia

In this paper we study the effect of market structure on the trade performance of South Korea, Taiwan, and Japan. We center our analysis on Korea and Taiwan, countries which have very different market structures: Korea has many large, vertically-integrated business groups known as chaebol, whereas business groups in Taiwan are smaller and horizontally-integrated in the production of intermediate inputs. The exports of these countries to the United States are compared using indexes of product variety and 'product mix', which are constructed at the 5-digit industry level. It is found that Taiwan tends to export a greater variety of products to the U.S. than Korea, and this holds across nearly all industries. In addition, Taiwan exports relatively more high-priced intermediate inputs, whereas Korea exports relatively more high-priced final goods. We argue that these results confirm the importance of market structure as a determinant of trade patterns.

Business Groups and Trade in East Asia: Part 2, Product Variety

We analyze the impact of market structure on the trade performance of South Korea, Taiwan and Japan. Korea has many large, vertically-integrated business groups known as chaebol, whereas business groups in Taiwan are smaller and more specialized in the production of intermediate inputs. We test the hypothesis that the greater vertical integration in Korea results in less product variety than for Taiwan, by constructing indexes of product variety and `product mix' in their exports to the United States. It is found that Taiwan tends to export a greater variety of products to the U.S. than Korea, and this holds across all industries. In addition, Taiwan exports relatively more high-priced intermediate inputs, whereas Korea exports relatively more high-priced final goods. A comparison with Japan is also presented, and we find that Japan has greater product variety in its sales to the U.S. than either Taiwan or Korea.

Business Groups and Trade in East Asia: Part 1, Networked Equilibria

We propose an economic model of business groups that allows for the cooperative behavior of groups of firms, where the number and size of each group is determined endogenously. In this framework, more than one configuration of groups can arise in equilibrium: several different types of business groups can occur, each of which is consistent with profit-maximization and is stable. This means that the economic logic does not fully determine the industrial structure, leaving scope for political and sociological factors to have a lasting influence. In a companion paper, we argue that the differing structures of business groups found in South Korea, Taiwan and Japan fit the stylized results from the model, and contrast the impact of these groups on the product variety of their country exports to the United States.

Business Groups and Trade in East Asia: Part 2, Product Variety

We analyze the impact of market structure on the trade performance of South Korea, Taiwan and Japan. Korea has many large, vertically-integrated business groups known as chaebol, whereas business groups in Taiwan are smaller and more specialized in the production of intermediate inputs. We test the hypothesis that the greater vertical integration in Korea results in less product variety than for Taiwan, by constructing indexes product variety and ""product mix"" in their exports to the United States. It is found that Taiwan tends to export a greater variety of products to the U.S. than Korea, and this holds across all industries. In addition, Taiwan exports relatively more high-priced intermediate inputs, whereas Korea exports relatively more high-priced final goods. A comparison with Japan is also presented, and we find that that Japan has greater product variety in its sales to the U.S. than either Taiwan or Korea

948-46 Preserved Cardiac Baroreflex Control of Renal Cortical Blood Flow in Advanced Heart Failure Patients: A Positron Emission Tomography Study

Cardiac baroreflex (CBR) control of forearm blood flow (FBF) is blunted or reversed in humans with heart failure (HF). but little is known about CBR control of renal cortical blood flow (RCBF) in HF due to technical limitations. Positron emission tomography (PET) 0–15 water is a new, precise method to measure RCBF quantitatively. We compared CBR control of RCBF and FBF (venous plethysmography) in 8 patients with HF (mean age, 47±3 y, ejection fraction 0.25±0.02) and 10 normal humans (mean age 35±5 y) during CBR unloading with phlebotomy (450ml). In 5 normals, cold pressor test was used as a strong, non-baroreflex mediated stimulus to vasoconstriction.ResultsPhlebotomy decreased central venous pressure (p <0.001), but did not change mean arterial pressure or heart rate in HF patients or controls. The major findings of the study are: 1) At rest, RCBF is markedly diminished in HF vs normals (2.4±0.1 vs 4.3±0.2ml/min/g, p < 0.001). 2) In normal humans during phlebotomy, FBF decreased substantially (basal vs phlebotomy: 3.3±0.4 vs 2.6±0.3 ml/min/100 ml, p=0.021, and RCBF decreased slightly, but significantly (basal vs phlebotomy: 4.3±0.2 vs 4.0±0.3 ml/min/g, p=0.01). 3) The small magnitude of reflex renal vasoconstriction is not explained by the inability of the renal circulation to vasoconstrict since the cold pressor stimulus induced substantial decreases in RCBF in normals (basal vs cold pressor: 4.4±0.1 vs 3.7±0.1 ml/min/g, p=0.003). 4) In humans with heart failure during phlebotomy, FBF did not change (basal vs phlebotomy: 2.6±0.3 vs 2.7±0.2 ml/min/100 ml, p=NS), but RCBF decreased slightly but significantly (basal vs phlebotomy: 2.4±0.1 vs 2.1±0.1 ml/min/g, p=0.01). Thus, in patients with heart failure, there is an abnormality in cardiopulmonary baroreflex control of the forearm circulation, but not the renal circulationConclusionThis study 1) shows the power of PET to study physiologic and pathophysiologic reflex control of the renal circulation in humans, and 2) describes the novel finding of selective dysfunction of cardiac baroreflex control of the forearm circulation, but its preservation of the renal circulation, in patients with heart failur

Groups and Trade in East Asia: Part 1, Networked Equilibria

We propose an economic model of business groups that allows for the cooperative behavior of groups of firms, where the number and size of each group is determined endogenously. In this framework, more than one configuration of groups that can arise in equilibrium: several different types of business groups can occur, each of which are consistent with profit-maximization and are stable. This means that the economic logic does not fully determine the industrial structure, leaving scope for political and sociological factors to have a lasting influence. In a companion paper , we argue that the differing structures of business groups found in South Korea, Taiwan and Japan fit the stylized results from the model, and contrast the impact of these groups on the product variety of their country exports to the United States

Peripheral sensitisation of nociceptors via G-proteindependent potentiation of mechanotransduction currents

Mechanical stimuli impinging on the skin are converted into electrical signals by mechanically gated ion channels located at the peripheral nerve endings of dorsal root ganglion (DRG) neurons. Under inflammatory conditions sensory neurons are commonly sensitised to mechanical stimuli; a putative mechanism that may contribute to such sensitisation of sensory neurons is enhanced responsiveness of mechanotransduction ion channels. Here we show that the algogens UTP and ATP potentiate mechanosensitive RA currents in peptidergic nociceptive DRG neurons and reduce thresholds for mechanically induced action potential firing in these neurones. Pharmacological characterisation suggests that this effect is mediated by the Gq-coupled P2Y2 nucleotide receptor. Moreover, using the in vitro skin nerve technique, we show that UTP also increases action potential firing rates in response to mechanical stimuli in a subpopulation of skin C-fibre nociceptors. Together our findings suggest that UTP sensitises a subpopulation of cutaneous C-fibre nociceptors via a previously undescribed G-protein-dependent potentiation of mechanically activated RA-type currents

Detection of weak gravitational lensing distortions of distant galaxies by cosmic dark matter at large scales

Most of the matter in the universe is not luminous and can be observed directly only through its gravitational effect. An emerging technique called weak gravitational lensing uses background galaxies to reveal the foreground dark matter distribution on large scales. Light from very distant galaxies travels to us through many intervening overdensities which gravitationally distort their apparent shapes. The observed ellipticity pattern of these distant galaxies thus encodes information about the large-scale structure of the universe, but attempts to measure this effect have been inconclusive due to systematic errors. We report the first detection of this ``cosmic shear'' using 145,000 background galaxies to reveal the dark matter distribution on angular scales up to half a degree in three separate lines of sight. The observed angular dependence of this effect is consistent with that predicted by two leading cosmological models, providing new and independent support for these models.Comment: 18 pages, 5 figures: To appear in Nature. (This replacement fixes tex errors and typos.