443 research outputs found
Trade Integration, Competiton, and the Decline in Exchange-rate Pass-through
Over the past twenty years, U.S. import prices have become less responsive to the exchange rate. We propose that this decline is a result of increased trade integration. To illustrate this effect, we develop an open economy DGE model in which there is strategic complementarity in price setting so that a firm's pricing decision depends on the prices set by its competitors. Because of the complementarity in price setting, a foreign exporter finds it optimal to vary its markup over cost in response to shocks that change the exchange rate, which insulates import prices from exchange rate movements. With increased trade integration, exporters have become more responsive to the prices of their competitors and this change in pricing behavior accounts for a significant portion of the observed decline in the sensitivity of U.S import prices to the exchange rate. Our environment of low pass-through also has important implications for the welfare benefits of trade integration: we find that the benefits are substantially reduced compared to an environment with complete pass-through.Pass-through, Trade Integration, Strategic Complementarities
Entry dynamics and the decline in exchange-rate pass-through
The degree of exchange-rate pass-through to import prices is low. An average passthrough estimate for the 1980s would be roughly 50 percent for the United States implying that, following a 10 percent depreciation of the dollar, a foreign exporter selling to the U.S. market would raise its price in the United States by 5 percent. Moreover, substantial evidence indicates that the degree of pass-through has since declined to about 30 percent. ; Gust, Leduc, and Vigfusson (2010) demonstrate that, in the presence of pricing complementarity, trade integration spurred by lower costs for importers can account for a significant portion of the decline in pass-through. In our framework, pass-through declines solely because of markup adjustments along the intensive margin. ; In this paper, we model how the entry and exit decisions of exporting firms affect passthrough. This is particularly important since the decline in pass-through has occurred as a greater concentration of foreign firms are exporting to the United States. ; We find that the effect of entry on pass-through is quantitatively small and is more than offset by the adjustment of markups that arise only along the intensive margin. Even though entry has a relatively small impact on pass-through, it nevertheless plays an important role in accounting for the secular rise in imports relative to GDP. In particular, our model suggests that over 3/4 of the rise in the U.S. import share since the early 1980s is due to trade in new goods. ; Thus, a key insight of this paper is that adjustment of markups that occur along the intensive margin are quantitatively more important in accounting for secular changes in pass-through than adjustments that occur along the extensive margin.
Measurements of noise in Josephson-effect mixers
We present new heterodyne receiver results obtained at 100 GHz using resistively-shunted Nb and NbN tunnel junctions. In addition, we have carried out accurate measurements of the available noise power of these devices at the L-band (1.5 GHz) IF frequency. Both the heterodyne and the output noise measurements show that the noise of these devices can be a factor of five or more higher than that predicted by the simple current-biased RSJ model. The noise approaches the appropriate thermal or thermal and shot noise limits for bias voltages where the nonlinearity is not strong (i.e., V>ICRN), but as expected from the RSJ model, can be significantly higher at the low voltages where the mixers are typically biased. The bias voltage dependence of the noise shows structure which is associated with resonances in the RF embedding circuit. Surprisingly, we find that changes in the high-frequency (100 GHz) impedance presented to the junction can dramatically affect the magnitude and voltage dependence of the low-frequency (1.5 GHz) noise. This emphasizes the necessity of very closely matching the junction to free space over a wide frequency range
A planar quasi-optical SIS receiver for array applications
A planar, quasi-optical SIS receiver operating at 230 GHz is described. The receiver consists of a 2 x 5 array of half wave dipole antennas with ten niobium-aluminum oxide-niobium SIS junctions on a quartz dielectric-filled parabola. The 1.4 GHz intermediate frequency is coupled from the mixer via coplanar strip transmission lines and 4:1 balun transformers. The receiver is operated at 4.2 K in a liquid helium immersion cryostat. We report accurate measurements of the performance of single receiver elements. A mixer noise temperature of 89 K DSB, receiver noise temperature of 156 K DSB, and conversion loss of 3 dB into a matched load have been obtained
Getting the elastic scattering length by observing inelastic collisions in ultracold metastable helium atoms
We report an experiment measuring simultaneously the temperatureand the flux
of ions produced by a cloud of triplet metastablehelium atoms at the
Bose-Einstein critical temperature. The onsetof condensation is revealed by a
sharp increase of the ion fluxduring evaporative cooling. Combining our
measurements withprevious measurements of ionization in a pure BEC,we extract
an improved value of the scattering length nm. The analysis
includes corrections takinginto accountthe effect of atomic interactions on the
criticaltemperature, and thus an independent measurement of the
scatteringlength would allow a new test of these calculations
Prospects for measurement and control of the scattering length of metastable helium using photoassociation techniques
A numerical investigation of two-laser photoassociation (PA) spectroscopy on
spin-polarized metastable helium (He*) atoms is presented within the context of
experimental observation of the least-bound energy level in the scattering
potential and subsequent determination of the s-wave scattering length.
Starting out from the model developed by Bohn and Julienne [Phys. Rev. A
\textbf{60}, (1999) 414], PA rate coefficients are obtained as a function of
the parameters of the two lasers. The rate coefficients are used to simulate
one- and two-laser PA spectra. The results demonstrate the feasibility of a
spectroscopic determination of the binding energy of the least-bound level. The
simulated spectra may be used as a guideline when designing such an experiment,
whereas the model may also be employed for fitting experimentally obtained PA
spectra. In addition, the prospects for substantial modification of the He*
scattering length by means of optical Feshbach resonances are considered.
Several experimental issues relating to the numerical investigation presented
here are discussed.Comment: 9 pages, 7 figure
Frequency shifts of photoassociative spectra of ultracold metastable Helium atoms : a new measurement of the s-wave scattering length
We observe light-induced frequency shifts in one-color photoassociative
spectra of magnetically trapped He atoms in the metastable
state. A pair of ultracold spin-polarized helium atoms is excited into
a molecular bound state in the purely long range potential connected to
the asymptote. The shift arises from the optical coupling of
the molecular excited bound state with the scattering states and the bound
states of two colliding atoms. We measure the frequency-shifts for
several ro-vibrational levels in the potential and find a linear
dependence on the photoassociation laser intensity. Comparison with a
theoretical analysis provides a good indication for the s-wave scattering
length of the quintet () potential, nm, which
is significantly lower than most previous results obtained by non-spectroscopic
methods.Comment: 7 pages, 4 figure
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