Policy Responses to the Post-bubble Adjustments in Japan: A Tentative Review

This paper provides a very tentative review of the monetary and prudential policy responses to the post-bubble adjustments in Japan. The adjustments after the collapse of the bubble have been prolonged due to (1) the rapid downward revision of the expected economic growth rate; (2) balance-sheet adjustments on the part of firms; and (3) the malfunctioning of the financial intermediary system stemming from its nonperforming-asset problem. We use four yardsticks, Marshallian k, Taylor rule, the equity yield spread, and the short-term real interest rate for assessing the monetary easing. The results suggest that the timing of policy reversal was swift and the magnitude of easing in the early phase could be viewed as broadly adequate for dealing with a normal business cycle. It is possible to argue that the effects of the bursting of the bubble might have not been sufficiently taken into account. It should be noted the outcome would not have differed greatly even if the drastic monetary easing that eventually took place had been decided at an earlier point in time without a fundamental cure of the nonperforming- asset problem. A considerable achievement of prudential policy in the period under review is that systemic risk was avoided with the cost being delayed in establishing a legal framework for handling troubled financial institutions and in organizing a comprehensive safety net. As a result of this delay, it took a long time to deal with the nonperforming- asset problem. This, in turn, posed a serious drag on the economy. Our preliminary conclusion about the lesson we should draw from this experience is the importance for the Bank of Japan of identifying the precise impacts of shocks on the economy as well as their transmission mechanism promptly and thereby minimizing adjustment costs. It should also be conducive for the Bank to address actively structural issues that may influence the effectiveness of its policy measures.

Initial rupture of earthquakes in the 1995 Ridgecrest, California Sequence

Close examination of the P waves from earthquakes ranging in size across several orders of magnitude shows that the shape of the initiation of the velocity waveforms is independent of the magnitude of the earthquake. A model in which earthquakes of all sizes have similar rupture initiation can explain the data. This suggests that it is difficult to estimate the eventual size of an earthquake from the initial portion of the waveform. Previously reported curvature seen in the beginning of some velocity waveforms can be largely explained as the effect of anelastic attenuation; thus there is little evidence for a departure from models of simple rupture initiation that grow dynamically from a small region. The results of this study indicate that any “precursory” radiation at seismic frequencies must emanate from a source region no larger than the equivalent of a M0.5 event (i.e. a characteristic length of ∼10 m). The size of the nucleation region for magnitude 0 to 5 earthquakes thus is not resolvable with the standard seismic instrumentation deployed in California

Harmonic excitation of mantle Rayleigh waves by the 1991 eruption of Mount Pinatubo, Philippines

An unusually long (at least two hours) seismic wave train having periods of about 230 sec was recorded at many worldwide seismic stations during the major eruption of Mount Pinatubo in the Philippines on June 15, 1991. This wave train exhibits two sharp spectral peaks at 228 and 270 sec. The group velocity, phase velocity, and the particle motion of this wave train indicate that it is a Rayleigh wave. The most probable excitation mechanism is acoustic coupling of atmospheric oscillations that were set off by continuous thermal energy flux from the volcano. The two spectral peaks correspond to the characteristic periods of acoustic and gravity modes of the Earth's atmosphere. The magnitude of the vertical single force equivalent to the acoustic coupling is 1.6×10^(17) dynes over a frequency band of 0.003 to 0.01 Hz. The results suggest the possibility of using acoustically coupled Rayleigh waves for detection, characterization and quantification of volcanic eruptions. Acoustic coupling of the atmosphere and the solid Earth provides a unique seismic source with long duration

Stress drops and radiated energies of aftershocks of the 1994 Northridge, California, earthquake

We study stress levels and radiated energy to infer the rupture characteristics and scaling relationships of aftershocks and other southern California earthquakes. We use empirical Green functions to obtain source time functions for 47 of the larger (M ≥ 4.0) aftershocks of the 1994 Northridge, California earthquake (M6.7). We estimate static and dynamic stress drops from the source time functions and compare them to well-calibrated estimates of the radiated energy. Our measurements of radiated energy are relatively low compared to the static stress drops, indicating that the static and dynamic stress drops are of similar magnitude. This is confirmed by our direct estimates of the dynamic stress drops. Combining our results for the Northridge aftershocks with data from other southern California earthquakes appears to show an increase in the ratio of radiated energy to moment, with increasing moment. There is no corresponding increase in the static stress drop. This systematic change in earthquake scaling from smaller to larger (M3 to M7) earthquakes suggests differences in rupture properties that may be attributed to differences of dynamic friction or stress levels on the faults

The 3 December 1988, Pasadena earthquake (M_L = 4.9) recorded with the very broadband system in Pasadena

Since 1 December 1987, a very broadband seismographic system has been in operation at the Kresge Laboratory of the California Institute of Technology. This system consists of the Streckeisen-1 very broadband sensor (Wielandt and Streckeisen, 1982), the Kinemetrics FBA-23 triaxial force balance accelerometer and a Quanterra data-logger with a 24-bit (for Streckeisen-1) and a 16-bit (for FBA-23) digitizer. The details of the data logger are described in Steim (1986). The overall dynamic range of this system is about 200 db. This system was constructed as a joint project between the California Institute of Technology, the U.S. Geological Survey, the University of Southern California and the International Research Institution for Seismology (IRIS), and is an element of the IRIS global network as well as the TERRAscope network of California Institute of Technology. A brief description of the system is given by Given et al. (1989)

Excitation of atmospheric oscillations by volcanic eruptions

We investigated the mechanism of atmospheric oscillations with periods of about 300 s which were observed for the 1991 Pinatubo and the 1982 El Chichón eruptions. Two distinct spectral peaks, at T = 270 and 230 s for the Pinatubo eruption and at T = 195 and 266 s for the El Chichón eruptions, have been reported. We found similar oscillations for the 1980 Mount St. Helens and the 1883 Krakatoa eruptions. To explain these observations, we investigated excitation problems for two types of idealized sources, “mass injection” and “energy injection” sources, placed in an isothermal atmosphere. In general, two modes of oscillations, “acoustic” and “gravity” modes, can be excited. For realistic atmospheric parameters, the acoustic and gravity modes have a period of 275 and 304 s, respectively. For a realistic time history of eruption, atmospheric oscillations with an amplitude of 50 to 100 Pa (0.5 to 1 mbar) can be excited by an energy injection source with a total energy of 10^17 J. This result is consistent with the observations and provides a physical basis for interpretation of atmospheric oscillations excited by volcanic eruptions

Relation Between Polycythemia and Function of Hemoglobin with Amino Acid Substitution in α1β2 Contact Hb Chesapeake [α92 (FG4) Arg→Leu ]and Hb J Cape Town [α92 (FG 4) Arg→Gln]

Two variants of abnormal hemoglobins with increased oxygen affinity, Hb Chesapeake (α92 Arg→Leu) and Hb J Cape Town (α92 Arg →Gln), were detected by isoelectric focusing during a population survey of residents of Aichi Prefecture. This was the first time for these abnormal hemoglobins to be found in Japanese. Following this discovery, a comparative study of the two variants was carried out employing isoelectric focusing, structural analysis (fingerprinting and amino acid analysis), functional analysis (oxygen equilibrium), dissociation into dimers, autoxidation, biosynthesis, and plasma erythropoietin level measurement. The carriers of Hb Chesapeake, who were heterozygous for the abnormal hemoglobin, showed mild polycythemia. Those of Hb J Cape Town, however, were free of polycythemia, although their hematological values (RBC, Ht and Hb) were close to the upper limits of the normal ranges. The results of the present study support the view that increased production of erythropoietin due to a tissue oxygen deficiency is not the only decisive factor for causation of polycythemia in variant hemoglobins with high oxygen affinity

Global Positioning System Resurvey of Southern California Seismic Network Stations

Systematic errors in travel-time data from local earthquakes can sometimes be traced to inaccuracies in the published seismic station coordinates. This prompted a resurvey of the stations of the Caltech/USGS Southern California Seismic Network (SCSN) using the Global Positioning System (GPS). We surveyed 241 stations of the SCSN using Trimble and Ashtech dual-frequency GPS receivers and calculated positions accurate to 3 m using differential positioning from carrier phase measurements. Twelve percent of the stations that were surveyed were found to be mislocated by more than 500 m. Stations of the TERRAscope and USC networks were also surveyed, as well as a network of portable seismic stations deployed shortly after the 1992 Joshua Tree and Landers earthquakes. The new coordinates and the offsets from the old coordinates are given below. The new coordinates are being used in SCSN locations as of 1 January 1994

Multiple Hepatic Lesions During Acute Leukemia Remissions

The US and CT manifestations of multiple small hepatic lesions of 15 patients during their remissions following chemotherapy for acute leukemia were reviewed. Liver biopsies established the diagnoses in 5 of the 15 patients. Despite their remissions, two cases had leukemic involvement. Others had microabscesses, 2 due to candida and 1 due to peptostreptococcus. Ultrasonographically, the microabscesses and leukemic involvement in the liver consisted of multiple round hypoechoic and target-like masses. With CT, these appeared as multiple zones of diminished attenuation. Only distal acoustic enhancement with US could differentiate these disease processes

Southern California Seismographic Network; report to the U.S. Geological Survey, August 21, 1990

On August 21, 1990, the U. S. Geological Survey held a meeting to review the status of regional seismic networks in the United States. The purpose of the meeting was to provide information to the U.S.G.S. to assist them in setting priorities for future funding of seismic networks in a time of increasingly tight budgets. Each of the networks was therefore asked to prepare a report describing their goals and accomplishments. Three specific questions were raised: how the objectives of the network have been met, the potential for future productivity and opportunities for additional funding