94 research outputs found
Hedging Price Volatility Using Fast Transport
Purchasing goods from distant locations introduces a significant lag between when a product is shipped and when it arrives. This is problematic for firms facing volatile demand, who must place orders before knowing the resolution of demand uncertainty. We provide a model in which airplanes bring producers and consumers together in time. Fast transport allows firms to respond quickly to favorable demand realizations and to limit the risk of unprofitably large quantities during low demand periods. Fast transport thus provides firms with a real option to smooth demand volatility. The model predicts that the likelihood and extent to which firms employ air shipments is increasing in the volatility of demand they face, decreasing in the air premium they must pay, and increasing in the contemporaneous realization of demand. We confirm all three conjectures using detailed US import data. We provide simple calculations of the option value associated with fast transport and relate it to variation in goods characteristics, technological change, and policies that liberalize trade in air services.
The Astropy Problem
The Astropy Project (http://astropy.org) is, in its own words, "a community
effort to develop a single core package for Astronomy in Python and foster
interoperability between Python astronomy packages." For five years this
project has been managed, written, and operated as a grassroots,
self-organized, almost entirely volunteer effort while the software is used by
the majority of the astronomical community. Despite this, the project has
always been and remains to this day effectively unfunded. Further, contributors
receive little or no formal recognition for creating and supporting what is now
critical software. This paper explores the problem in detail, outlines possible
solutions to correct this, and presents a few suggestions on how to address the
sustainability of general purpose astronomical software
Understanding the circumgalactic medium is critical for understanding galaxy evolution
Galaxies evolve under the influence of gas flows between their interstellar
medium and their surrounding gaseous halos known as the circumgalactic medium
(CGM). The CGM is a major reservoir of galactic baryons and metals, and plays a
key role in the long cycles of accretion, feedback, and recycling of gas that
drive star formation. In order to fully understand the physical processes at
work within galaxies, it is therefore essential to have a firm understanding of
the composition, structure, kinematics, thermodynamics, and evolution of the
CGM. In this white paper we outline connections between the CGM and galactic
star formation histories, internal kinematics, chemical evolution, quenching,
satellite evolution, dark matter halo occupation, and the reionization of the
larger-scale intergalactic medium in light of the advances that will be made on
these topics in the 2020s. We argue that, in the next decade, fundamental
progress on all of these major issues depends critically on improved empirical
characterization and theoretical understanding of the CGM. In particular, we
discuss how future advances in spatially-resolved CGM observations at high
spectral resolution, broader characterization of the CGM across galaxy mass and
redshift, and expected breakthroughs in cosmological hydrodynamic simulations
will help resolve these major problems in galaxy evolution.Comment: Astro2020 Decadal Science White Pape
Societal-level versus individual-level predictions of ethical behavior: a 48-society study of collectivism and individualism
Is the societal-level of analysis sufficient today to understand the values of those in the global workforce? Or are individual-level analyses more appropriate for assessing the influence of values on ethical behaviors across country workforces? Using multi-level analyses for a 48-society sample, we test the utility of both the societal-level and individual-level dimensions of collectivism and individualism values for predicting ethical behaviors of business professionals. Our values-based behavioral analysis indicates that values at the individual-level make a more significant contribution to explaining variance in ethical behaviors than do values at the societal-level. Implicitly, our findings question the soundness of using societal-level values measures. Implications for international business research are discussed
Atlantic Meridional Overturning Circulation: Observed Transport and Variability
The Atlantic Meridional Overturning Circulation (AMOC) extends from the Southern Ocean to the northern North Atlantic, transporting heat northwards throughout the South and North Atlantic, and sinking carbon and nutrients into the deep ocean. Climate models indicate that changes to the AMOC both herald and drive climate shifts. Intensive trans-basin AMOC observational systems have been put in place to continuously monitor meridional volume transport variability, and in some cases, heat, freshwater and carbon transport. These observational programs have been used to diagnose the magnitude and origins of transport variability, and to investigate impacts of variability on essential climate variables such as sea surface temperature, ocean heat content and coastal sea level. AMOC observing approaches vary between the different systems, ranging from trans-basin arrays (OSNAP, RAPID 26°N, 11°S, SAMBA 34.5°S) to arrays concentrating on western boundaries (e.g., RAPID WAVE, MOVE 16°N). In this paper, we outline the different approaches (aims, strengths and limitations) and summarize the key results to date. We also discuss alternate approaches for capturing AMOC variability including direct estimates (e.g., using sea level, bottom pressure, and hydrography from autonomous profiling floats), indirect estimates applying budgetary approaches, state estimates or ocean reanalyses, and proxies. Based on the existing observations and their results, and the potential of new observational and formal synthesis approaches, we make suggestions as to how to evaluate a comprehensive, future-proof observational network of the AMOC to deepen our understanding of the AMOC and its role in global climate
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