Welfare and excess volatility of exchange rates

We study the properties of a GEI model with nominal assets, outside money (injected into the economy as in Magill and Quinzii), and multiple currencies. We analyze the existence of monetary equilibria and the structure of the equilibrium set under two different assumptions on the determination of the exchange rates. If currencies are perfect substitutes, equilibrium allocations are indeterminate and, generically, sunspot equilibria exist. Generically, given a nonsunspot equilibrium, there are Pareto improving (and Pareto worsening) sunspot equilibria associated with an increase in the volatility of the future exchange rates. We interpret this property as showing that, in general, there is no clear-cut effect on welfare of the excess volatility of exchange rates, even when due to purely extrinsic phenomena.

Income taxes, subsidies to education, and investments in human capital

We study a two-sector economy with investments in human and physical capital and imperfect labor markets. Human and physical capital are heterogeneous. Workers and firms endogenously select the sector they are active in, and choose the amount of their sector-specific investments in human and physical capital. To enter the high-skill sector, workers must pay a fixed cost that we interpret as direct cost of education. Given the distribution of the agents across sectors, at equilibrium, in each sector there is underinvestment in both human and physical capital, due to non-contractibility of investments. A second source of inefficiency is related to the self-selection of the agents into the two sectors. It typically induces too many workers to invest in education. Under suitable restrictions on the parameters, the joint effect of the two distortions is that equilibria are characterized by too many people investing too little effort in the high skill sector. We also analyze the welfare properties of equilibria and study the effects of several tax-subsidy policies on the total expected surplus.

Investments in education and welfare in a two-sector, random matching economy

We consider a random matching model where heterogeneous agents choose optimally to invest time and real resources in education. Generically, there is a steady state equilibrium, where some agents, but not all of them, invest. Regular steady state equilibria are constrained inefficient in a strong sense. The Hosios (1990) condition is neither necessary, nor sufficient, for constrained efficiency. We also provide restrictions on the fundamentals sufficient to guarantee that equilibria are characterized by overeducation (or undereducation), present some results on their comparative statics properties, and discuss the nature of welfare improving policies.

Long-Range Order in Electronic Transport through Disordered Metal Films

Ultracold atom magnetic field microscopy enables the probing of current flow patterns in planar structures with unprecedented sensitivity. In polycrystalline metal (gold) films we observe long-range correlations forming organized patterns oriented at +/- 45 deg relative to the mean current flow, even at room temperature and at length scales orders of magnitude larger than the diffusion length or the grain size. The preference to form patterns at these angles is a direct consequence of universal scattering properties at defects. The observed amplitude of the current direction fluctuations scales inversely to that expected from the relative thickness variations, the grain size and the defect concentration, all determined independently by standard methods. This indicates that ultracold atom magnetometry enables new insight into the interplay between disorder and transport

Re-examining the Kuleshov effect

The purpose of this study was to further explore the Kuleshov effect, originally examined by Soviet filmmaker Lev Kuleshov through a variety of editing experiments in the early 1920's. Concluding that audience members were likely to view a neutral-faced actor's emotions based on the stimuli he was associated with (e.g., a bowl of soup for hunger), this observation became universally accepted. Although the influence of the Kuleshov effect has been well documented in a variety of academic texts (and integrated into empirical research), the study itself has never been fully replicated in its original form. Expanding on the qualitative research of Prince & Hensley (1992), this study aimed to test the strength of Lev Kuleshov’s initial experiment through adapted replication, as well as examine the influence gender differences within the target face (actor) may have on the participant’s interpretation of facial emotional expression. Adapted replication consisted of utilizing updated video clips, including both male and female actors, and providing regulated questionnaires to all participants (rather than a freeform, post-experiment discussion). It was expected that the Kuleshov effect would be observed, and the gender of the actor would have no effect on the participants’ responses. 150 undergraduate students from the University of Pittsburgh were included in this study, with each participant viewing (10) short clips and ranking the degree to which they believe the actor was expressing (8) different emotions (via a Likert-type scale). The results of this study showed the Kuleshov effect being observed in a more nuanced manner, with significant differences existing in specific emotion conditions for the target face. Future research on this subject could feature the inclusion of different participant populations, incorporate neuroimaging techniques, or examine gender as a primary research question

Unusual clear cell variant of epithelioid mesothelioma

Clear cell mesothelioma is an extremely rare neoplasm of the pleura, which can easily be mistaken for a metastasis of clear cell carcinoma to the pleura. We report here the histochemical, immunohistochemical, and ultrastructural aspects of a new case of clear cell pleural mesothelioma in a 52-year-old man with no known asbestos exposure. He was admitted to the hospital for recurrent pleural effusion, which was negative for neoplastic cells at the cytologic examination. A partial decortication of the right pleura was performed. The morphologic, immunohistochemical, and ultrastructural features reported for this case are consistent with the diagnosis of clear cell mesothelioma. The differential diagnosis and immunohistochemical features in comparison with other clear cell neoplasms are discussed