Power Spectrum Analysis of the OMC1 Image at 1.1 mm Wavelength

We present a 1.1mm emission map of the OMC1 region observed with AzTEC, a new large-format array composed of 144 silicon-nitride micromesh bolometers, that was in use at the James Clerk Maxwell Telescope (JCMT). These AzTEC observations reveal dozens of cloud cores and a tail of filaments in a manner that is almost identical to the submillimeter continuum emission of the entire OMC1 region at 450 and 850 micronm. We perform Fourier analysis of the image with a modified periodogram and the density power spectrum, which provides the distribution of the length scale of the structures, is determined. The expected value of the periodogram converges to the resulting power spectrum in the mean squared sense. The present analysis reveals that the power spectrum steepens at relatively smaller scales. At larger scales, the spectrum flattens and the power law becomes shallower. The power spectra of the 1.1mm emission show clear deviations from a single power law. We find that at least three components of power law might be fitted to the calculated power spectrum of the 1.1mm emission. The slope of the best fit power law, \gamma ~ -2.7 is similar to those values found in numerical simulations. The effects of beam size and the noise spectrum on the shape and slope of the power spectrum are also included in the present analysis. The slope of the power law changes significantly at higher spatial frequency as the beam size increases.Comment: 7 pages, 2 figures, Journal of the Korean Astronomical Society, vol. 45, pp.93-99; For Figure 1, please refer to http://jkas.kas.org/journals/2012v45n4/v45n4p093_skim.pd

Incomplete Intertemporal Consumption Smoothing and Incomplete Risksharing

This paper develops a method to estimate jointly the degree of (possibly incomplete) intertemporal consumption smoothing and the degree of (possibly incomplete) international/interregional risksharing. This approach generalizes and improves upon studies that either examine only intertemporal consumption smoothing, or analyze risksharing by making an extreme assumption on intertemporal consumption smoothing, or by adopting a purely empirical framework. The method is applied to the US states and OECD and EU countries to analyze how the degrees of risksharing and intertemporal consumption smoothing differ within a country and across countries. The empirical results suggest that: 1) regardless of the assumption on the degree of intertemporal consumption smoothing, the degree of risksharing within a country is larger than across countries 2) the degree of intertemporal consumption smoothing within a country is also larger than across countries, contrary to the findings of past channel studies. Finally, this paper also provides some foundations and suggests limitations of the empirical literature on channels of risksharing and intertemporal consumption smoothing.Intertemporal consumption smoothing, risksharing, channels of risksharing, international vs. intranational

Consumption Smoothing Channels in Open Economies

We recognize that intertemporal models of the current account (Frankel and Razin with Yuan 1996, or Baxter and Crucini 1993) imply a theory of consumption smoothing channels, and thus we build an empirical model on the theoretical foundations of Sachs (1982)'s optimizing model in order to analyze the intertemporal smoothing role of saving components (fixed investments, inventories and trade balance). The estimation is conducted in a structural VAR framework, in which the minimal identifying restrictions are consistent with both the 'intertemporal approach to the current account' and the empirical consumption smoothing literature. Through the use of impulse response functions following different types of shocks, we find that for the OECD countries the bulk of intertemporal smoothing has been carried out domestically, through gross fixed investments and inventories, but the trade balance has also played a relevant - albeit volatile - smoothing role. We also determine the dynamic role of each component: the trade balance and inventories are mostly used as short-run smoothing tools while fixed investment provides more and more smoothing over time. Since our framework can accommodate various models of the current account, we can address some empirical puzzles, such as the 'excess sensitivity of investment' anomaly (Glick and Rogoff, JME 1995) and the 'saving-investment puzzle' (Feldstein and Horioka, EJ 1980).Consumption smoothing channels; Intertemporal approach to the current account; VAR; Feldstein-Horioka puzzle; Capital mobility.

Dynamic Risk Sharing in the United States and Europe

This paper uses a panel VAR model to improve upon the existing literature on interregional risk sharing channels (e.g. Asdrubali, Sorensen and Yosha, 1996) in several respects. First, it endogenizes the output process within a multi-equation framework, capturing the dynamic feedback between output and various risk sharing channels. Second, in contrast to previous research's analysis of static risk sharing in the presence of exogenous output shocks, it uses impulse response functions to trace the role of each risk sharing channel over time, in the presence of different structural shocks (temporary vs. persistent and output vs. risk sharing channels). Third, the paper extends the risk sharing channels typically analyzed, by considering the consumption smoothing role of changes in the nominal exchange rate and relative commodity prices across regions. The empirical method is applied to the U.S. states, 23 OECD countries, and 15 countries in the European Union from 1960 to 1990. Regarding the dynamic responses of each risk sharing channel to exogenous output shocks, the results suggest that the dynamics are substantially different among different channels. First, most capital market smoothing is achieved on impact while fiscal smoothing is achieved over time. Second, credit market plays a positive role on impact, but a negative role later. Regarding the substitutability of channels, first, fiscal smoothing is fully substituted by credit market channel in the U.S. while only half of capital market smoothing is substituted in OECD and EU countries. Second, fiscal smoothing is not substituted by any other channels in the U.S. while half of fiscal smoothing is substituted by credit market smoothing in the OECD and EU countries. The results also suggest that nominal and real exchange rate movements are very important in analyzing international risk sharing in OECD and EU countries.

International Capital Flows and Boom-Bust Cycles in the Asia Pacific Region

This paper documents evidence of business cycle synchronization in selected Asia Pacific countries in the 1990s. We explain business cycle synchronization by the channel of international capital flows. Using the VAR method, we find that most Asian countries experience boom-bust cycles following capital inflows, where the boom in output is mostly driven by consumption and investment. Empirical evidence shows that capital flows in the region are highly correlated, which supports the conclusion that capital market liberalization has contributed to business cycle synchronization in Asia. We also find that business cycles in the Asian crisis countries are highly synchronized with those in Japan.business cycle synchronization, capital flows, boom-bust cycles, financial integration

Fear of Floating in East Asia

We examine the de facto exchange rate arrangements in East Asia by applying the methods suggested by Calvo and Reinhart (2002) and Kim (2004). Estimation results suggest that three East Asian countries in our sample adopted a hard peg or a peg with capital account restrictions in the post-crisis period. Five East Asian countries in our sample moved toward a more flexible exchange rate arrangement in the post-crisis period. At least three of these five countries (Korea, Indonesia and Thailand) achieved the level of exchange rate flexibility that is close to the level accomplished in the free floater such as Australia. These results suggest that “Fear of Floating” of East Asian countries is not prevalent in the post-crisis period and that the bi-polar view has some support in East Asian samples.Bi-polar View, De Facto Exchange Rate Arrangements, De Jure Exchange Rate Arrangements, East Asia, Fear of Floating

The Impact of Capital Inflows on Emerging East Asian Economies: Is Too Much Money Chasing Too Little Good?

In recent years, emerging East Asian economies have experienced large capital inflows-especially a surge in portfolio inflows-and an appreciation of asset prices such as equities, land, and both nominal and real exchange rates. The paper reviews why a surge in capital inflows can increase asset prices, and then empirically investigates the effects by employing a panel vector autoregression (VAR) model. The empirical results suggest that capital inflows have indeed contributed to the asset price appreciation in this region, although capital inflow shocks explain a relatively small part of asset price fluctuations. How to manage these capital inflows is also discussed.Capital inflows; portfolio inflows; asset prices

Real and Financial Integration in East Asia

We examine the real and financial integration of East Asian economies, comparing the degree of real versus financial integration, the degree of global versus regional integration, and the extent of integration before versus after the 1997/98 financial crisis in East Asian economies. We analyze price and quantity measures of integration such as the size of intra- and inter-regional trade, cross-border financial assets, correlation of stock returns, and interest rate differentials. In addition, we adopt a panel VAR approach of investigating cross-country output inter-dependence and consumption relation in order to infer the macroeconomic consequences of real and financial integration on East Asian economies. The empirical investigations suggest that (i) using the quantity measure there is a significant increase in real integration within East Asia; (ii) real-side integration based on output linkage increased substantially after the Asian crisis, both regionally and globally; (iii) although quantity and price measures showed some degree of increased financial integration after the crisis, the cross-country consumption relation did not change much; (iv) the degree of regional financial integration within Asia is far smaller than the degree of global financial integration, based on the consumption-based measure; and (v) financial integration lags real integration, especially for regional integration within Asia.Trade and financial integration; global and regional integration; risk sharing; East Asia