Long-run real exchange rate changes and the properties of the variance of k-differences

Engel (1999) computes the variance of k-differences for each time horizon us- ing the method of Cochrane (1988) in order to measure the importance of the traded goods component in U.S. real exchange rate movements. The importance of traded goods should decrease as the horizon increases if the law of one price holds for traded goods in the long run. However, Engel ?nds that the variance of k-di¤erences decreases only initially and then increases as k approaches the sample size. He interpets the increasing variance as evidence of an increase in the long-run importance of the traded goods component. By contrast, we show that the variance of k-di¤erences tends to return to the initial value as k approaches the sample size whether the variable is stationary or unit root nonstationary. Our results imply that the increasing variances for k-values close to the sample size cannot be inter- preted as evidence of an increase in the importance of the traded goods component in the long run. We ?nd that our test results regarding the variance of k-di¤erences are consistent with smaller importance of the traded goods component in the longer run.Real exchange rate, Variance ratio, Traded and nontraded goods

Small-scale Effects of Thermal Inflation on Halo Abundance at High-zz, Galaxy Substructure Abundance and 21-cm Power Spectrum

We study the impact of thermal inflation on the formation of cosmological structures and present astrophysical observables which can be used to constrain and possibly probe the thermal inflation scenario. These are dark matter halo abundance at high redshifts, satellite galaxy abundance in the Milky Way, and fluctuation in the 21-cm radiation background before the epoch of reionization. The thermal inflation scenario leaves a characteristic signature on the matter power spectrum by boosting the amplitude at a specific wavenumber determined by the number of e-foldings during thermal inflation ($N_{\rm bc}$), and strongly suppressing the amplitude for modes at smaller scales. For a reasonable range of parameter space, one of the consequences is the suppression of minihalo formation at high redshifts and that of satellite galaxies in the Milky Way. While this effect is substantial, it is degenerate with other cosmological or astrophysical effects. The power spectrum of the 21-cm background probes this impact more directly, and its observation may be the best way to constrain the thermal inflation scenario due to the characteristic signature in the power spectrum. The Square Kilometre Array (SKA) in phase 1 (SKA1) has sensitivity large enough to achieve this goal for models with $N_{\rm bc}\gtrsim 26$ if a 10000-hr observation is performed. The final phase SKA, with anticipated sensitivity about an order of magnitude higher, seems more promising and will cover a wider parameter space.Comment: 28 pages, 8 figure

3D avatar seller's effect on online consumer's purchasing behavior: a trust transference perspective

The emerging 3D virtual worlds attract more and more people to participate in the virtual environment, creating a new market for business to sell their products. In 3D virtual worlds, members mainly interact with each other through avatars. The selling process is fulfilled through the shop avatars. How businesses sell their products successfully to the potential customers and eventually persuade the customer to purchase the product is an essential question. Trust played a key role in the selling process. In the general selling process, trust was established through the sales person. In the virtual world environment, could the trust be established between the sales avatars and customer avatars This paper aims at answering this question by examining the trust transference process in the 3D virtual world environment. An experiment was conducted to categorize the avatars into attractive and expert ones. The research result first suggest that trust formed in a 3D avatar seller could be transferred to a selling company and a product but for an expert 3D avatar seller, trust transferred to the company and product results in intent to purchase. Trust in a 3D avatar seller is transferred to trust in a product and a company and furthermore, an expert avatar can affect a consumer's intent to purchase. In the case of an attractive 3D avatar, although trust is transferred, it is only to the point of intent to purchase