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A Copula-Based Joint Model of Commute Mode Choice and Number of Non-Work Stops during the Commute
At the time of publication A. Portoghese, E. Spissu, and I. Meloni were at University of Cagliari, and C.R. Bhat and N. Eluru were at the University of Texas at Austin.In this paper, in the spirit of a tour-based frame of analysis, we examine the commute mode choice
and the number of non-work stops during the commute. Understanding the mode and activity stop
dimensions of weekday commute travel is important since the highest level of weekday traffic
congestion in urban areas occurs during the commute periods. The paper employs a copula-based
joint multinomial logit – ordered modeling framework in which commute mode choice is modeled
using a multinomial logit formulation and the number of commute stops is modeled using an ordered
response formulation. The data used in this study are drawn from the “Time use” multipurpose
survey conducted between 2002 and 2003 by the Turin Town Council and the Italian National
Institute of Statistics (ISTAT) in the Greater Turin metropolitan area of Italy. The results highlight
the importance of accommodating the inter-relationship between commute mode choice and
commute stops behavior. The results also point to the stronger effect of household responsibilities
and demographic characteristics in the Italian context compared to the US context.Civil, Architectural, and Environmental Engineerin
Preferential concentration of inertial sub-kolmogorov particles. The roles of mass loading of particles, Stokes and Reynolds numbers
Turbulent flows laden with inertial particles present multiple open questions
and are a subject of great interest in current research. Due to their higher
density compared to the carrier fluid, inertial particles tend to form high
concentration regions, i.e. clusters, and low concentration regions, i.e.
voids, due to the interaction with the turbulence. In this work, we present an
experimental investigation of the clustering phenomenon of heavy sub-Kolmogorov
particles in homogeneous isotropic turbulent flows. Three control parameters
have been varied over significant ranges: ,
and volume fraction . The scaling of clustering characteristics, such as the distribution
of Vorono\"i areas and the dimensions of cluster and void regions, with the
three parameters are discussed. In particular, for the polydispersed size
distributions considered here, clustering is found to be enhanced strongly
(quasi-linearly) by and noticeably (with a square-root
dependency) with , while the cluster and void sizes, scaled with the
Kolmogorov lengthscale , are driven primarily by . Cluster
length scales up to , measured
at the highest , while void length
scaled also with is typically two times larger ().
The lack of sensitivity of the above characteristics to the Stokes number lends
support to the "sweep-stick" particle accumulation scenario. The non-negligible
influence of the volume fraction, however, is not considered by that model and
can be connected with collective effects
The Global Spread of Stock Exchange, 1980-1998
Nations opened local stock exchanges at a rapid pace during the late 1980s and 1990s, creating a channel for investment capital from wealthy industrial nations to "emerging markets" as well as a mechanism for institutional change in local economies. This study examines the local and global processes by which exchanges spread, examining all nations "at risk" during the 1980s and 1990s. We find that local factors influencing the creation of stock exchanges included the size of the economy (overall and relative to population size); the legacy of colonialism; and a recent transition to multi-party democracy. Global factors associated with creating exchanges included levels of prior investment by multinationals; IMF "structural adjustment" aid; centrality in trade flows; and regional "contagion." In contrast to prior work in financial economics, we find no evidence for the influence of legal tradition, and contrary to the implications of dependency theory, we find no sign that foreign capital penetration affects the creation of exchanges. We also find no consistent evidence for the influence of stock exchanges on inequality or human development at the national level, above and beyond their effect on economic and population growth. The results indicate that globalization is usefully construed as a process analogous to institutional diffusion at the organization level.http://deepblue.lib.umich.edu/bitstream/2027.42/39725/3/wp341.pd
Rent Appropriation in Strategic Alliances: A Study of Technical Alliances in Pharmaceutical Industry
Many existing alliance studies have investigated how embedded relations create superior value for organizations. The role of network structure in rent appropriation or pie splitting, however, has been underexplored. We propose that favorable locations in interorganizational networks provide firms with superior opportunities for appropriating more economic benefits from alliances than their partners do. Specifically, we argue that partners’ asymmetric network positions will lead to unequal brokerage positions that promote disparate levels of information gathering, monitoring, and bargaining power, which lead to differing capacities to appropriate value. This in turn results in variations in market performance. We also propose this brokerage position exacerbates existing inequalities such as commercial capital; thus, available firm resources will moderate such network effects. Evidence is presented in the form of market response to technology alliance announcements from a set of pharmaceutical firms. In general, we find that firms within central network positions and those spanning structural holes have higher returns than their partners. In addition, we show that this relationship is contingent upon available firm resources
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