Atmospheric temperature tides in the tropical upper troposphere and lower stratosphere

Atmospheric thermal tides are global-scale waves with periods that are harmonics of a solar day, mainly excited by diurnally varying diabatic heating in the troposphere and the stratosphere. Some recent studies suggested that the tidal temperature variations in the TTL might affect the appearance of cirrus clouds and, thus, the dehydration process. It should be noted, however, that the global pattern of diurnal temperature variations in the TTL still remains unclear. In this study, we aim at revealing the 3D structure of diurnal temperature variations around the TTL, including its seasonal variations, by using data from global reanalyses for the period of 2002-2006. It is found that the Sun synchronous tides have amplitudes of ~0.3 K (~0.5 K) at 100 hPa (70 hPa) in January. Superposed on these components, the non-Sun-synchronous tides are strong over the continent (South America, Africa); these may be excited by latent heat release associated with deep convections there. The total (i.e., Sun-synchronous plus non-Sun-synchronous) diurnal temperature amplitudes reach ~0.5 K (~1 K) at maxima at 100 hPa (70 hPa) in January. The seasonality and the impact on the dehydration will be discussed in the presentation

"Hotelling's Spatial Competition Reconsidered"

Oligopoly models are usually analyzed in the context of two firms anticipating that market outcomes would be qualitatively similar in the case of three or more firms. This is not an exception in the literature on Hotelling's location-then-price competition. In this paper, we show that the main findings in Hotelling's duopoly, brand bunching and the max-min principle of product differentiation no longer hold once three or more firms are allowed to enter the market. That is, oligopolists with three or more firms proliferate brands and neither maximize nor minimize product differentiation.

International Impacts on Domestic Political Economy: A Case of Japanese General Elections

The objective of this paper is twofold. First, this paper emphasizes that in a parliamentary system, such as in Japan, election timings become endogenous, in that good economic performances tend to trigger elections. Second, impacts of international factors, such as foreign exchange reserves and elections of the United States, on domestic economic performances will be examined in the context of political business cycles. This paper finds only a limited link between economic performances and international variables, except one that upcoming elections in the United States tend to cause a higher rate of growth in Japan. Evidence suggests that although blatant policies, such as a beggar-thy-neighbor policy, were not adopted, a more subtle international cooperation, in the form of Japanese expansion to pill up the United States economy, have been used.

Interventions and Japanese Economic Recovery

This paper attempts to explain possible reasons and objectives behind the 35 trillion yen (7% of GDP) interventions conducted by the Japanese monetary authorities from January 2003 to March 2004, and to discuss whether the interventions achieved the presumed objectives: making the movement of the yen flexible but orderly, and helping economic recovery. The motivation of starting intervention in January 2003 was to keep the yen from appreciating in the midst of financial and macroeconomic weakness. The economy started to show some strength in the second half of 2003, but interventions continued, with a brief pause in September. Reasons for interventions after September are two-fold. First, the interventions provided opportunities for unsterilized interventions. Second, the monetary authorities were extremely sensitive to speculative activities in the market.Intervention of foreign exchange market, the yen, monetary policy, Japanese economy

Use of (Time-Domain) Vector Autoregressions to Test Uncovered Interest Parity

In this paper, a vector autoregression model (VAR) is proposed in order to test uncovered interest parity (UIP) in the foreign exchange market. Consider a VAR system of the spot exchange rate (yen/dollar), the domestic (US) interest rate and the foreign (Japanese) interest rate, describing the interdependence of the domestic and international financia lmarkets. Uncovered interest parity is stated as a null hypothesis that the current difference between the two interest rates is equal to the difference between the expected future (log of) exchange rate and the (log of) current spot exchange rate. Note that the VAR system will yield the expected future spot exchange rate as a k-step ahead unconditional prediction. Hence, the null hypothesis is stated as nonlinear cross-equational restrictions for the three-equation VAR system. Then UIP is tested by the Wald test between the unrestricted and restricted systems. A test of UIP with a maintained hypothesis of covered interest parity, becomes a hypothesis test of efficiency without risk premium, that is,the forward exchange rate isthe unbiased predictor of the future spot exchange rate, and information is efficiently used in its prediction. Our results are compared to the efficiency test with a single equation using the Hansen-Hodrick procedure for the same data set.

"Self-organizing Marketplaces"

Dynamics of retail firms in marketplaces is analyzed, assuming that firms compete within a marketplace as well as between marketplaces under monopolistically competition. The number, size, and location of marketplaces or edge cities are analytically obtained, which is hardly done in the previous literature. Furthermore, extending the model to a two-dimensional space, Christaller-Losch system of hexagonal market areas is analytically derived.