3,564 research outputs found
Industrial Groupings and Strategic FDI: Theory and Evidence
We show that industrial ownership structures, such as keiretsu groupings in Japan, may significantly impact firms' incentives to engage in FDI. While the previous literature has mainly focused on the cost of capital advantages enjoyed by keiretsu firms, this paper examines two relatively unexplored channels by which ownership structure matters for FDI incentives. The first channel involves the direct incentives generated via standard product and factor market interactions whereby keiretsu firms with cross-ownership consider more directly the congestion effects of further FDI into a market. The second channel involves the indirect incentives generated by sharing of information across keiretsu firms which reduces entry costs for subsequent FDI. Using data on Japanese FDI activity by both keiretsu and non-keiretsu manufacturing firms, we find evidence to support the importance of the second channel (information-sharing incentives) as an explanation for firm-level FDI patterns, but not for the first channel.
The Mass Assembly Histories of Galaxies of Various Morphologies in the GOODS Fields
We present an analysis of the growth of stellar mass with cosmic time
partitioned according to galaxy morphology. Using a well-defined catalog of
2150 galaxies based, in part, on archival data in the GOODS fields, we assign
morphological types in three broad classes (Ellipticals, Spirals,
Peculiar/Irregulars) to a limit of z_AB=22.5 and make the resulting catalog
publicly available. We combine redshift information, optical photometry from
the GOODS catalog and deep K-band imaging to assign stellar masses. We find
little evolution in the form of the galaxy stellar mass function from z~1 to
z=0, especially at the high mass end where our results are most robust.
Although the population of massive galaxies is relatively well established at
z~1, its morphological mix continues to change, with an increasing proportion
of early-type galaxies at later times. By constructing type-dependent stellar
mass functions, we show that in each of three redshift intervals, E/S0's
dominate the higher mass population, while spirals are favored at lower masses.
This transition occurs at a stellar mass of 2--3 times 10^{10} Msun at z~0.3
(similar to local studies) but there is evidence that the relevant mass scale
moves to higher mass at earlier epochs. Such evolution may represent the
morphological extension of the ``downsizing'' phenomenon, in which the most
massive galaxies stop forming stars first, with lower mass galaxies becoming
quiescent later. We infer that more massive galaxies evolve into spheroidal
systems at earlier times, and that this morphological transformation may only
be completed 1--2 Gyr after the galaxies emerge from their active star forming
phase. We discuss several lines of evidence suggesting that merging may play a
key role in generating this pattern of evolution.Comment: 24 pages, 1 table, 8 figures, accepted for publication in Ap
Repeated Lobbying by Commercial Lobbyists and Special Interests
Using a model of repeated agency, we explain previously unexplained features of the real-world lobbying industry. Lobbying is divided between direct representation by special interests to policymakers, and indirect representation where special interests employ professional intermediaries called commercial lobbyists to lobby policymakers on their behalf. Our analytical structure allows us to explain several trends in lobbying. For example, using the observation that in the U.S. over the last 20 years policymakers have spent an increasing amount of their time fundraising as opposed to legislating, we are able to explain why the share of commercial lobbyist activity in total lobbying has risen dramatically and now constitutes over 60% of the total. The key scarce resource in our analysis is policymakers’ time. They allocate this resource via implicit repeated agency contracts which are used to incent special interests and commercial lobbyists to provide a mix of financial contributions and information on policy proposals. These implicit agency contracts solve both an information problem in the presence of unverifiable policy information and a contracting problem in the absence of legal enforcement. These repeated relationship, that are often described using the pejorative term cronyism in the popular press, may in certain circumstances be welfare improving
A Slow Merger History of Field Galaxies Since z~1
Using deep infrared observations conducted with the CISCO imager on the
Subaru Telescope, we investigate the field-corrected pair fraction and the
implied merger rate of galaxies in redshift survey fields with Hubble Space
Telescope imaging. In the redshift interval, 0.5 < z < 1.5, the fraction of
infrared-selected pairs increases only modestly with redshift to 7% +- 6% at
z~1. This is nearly a factor of three less than the fraction, 22% +- 8%,
determined using the same technique on HST optical images and as measured in a
previous similar study. Tests support the hypothesis that optical pair
fractions at z~1 are inflated by bright star-forming regions that are unlikely
to be representative of the underlying mass distribution. By determining
stellar masses for the companions, we estimate the mass accretion rate
associated with merging galaxies. At z~1, we estimate this to be 2x10^{9 +-
0.2} solar masses per galaxy per Gyr. Although uncertainties remain, our
results suggest that the growth of galaxies via the accretion of pre-existing
fragments remains as significant a phenomenon in the redshift range studied as
that estimated from ongoing star formation in independent surveys.Comment: 5 pages, accepted for publication in ApJ Letter
Corruption, Decentralization and Yardstick Competition
16 p.Several empirical studies have found a negative relationship between corruption and the decentralization of the powers to tax and spend. In this paper we explain this phenomenon using a model of Yardstick Competition. Further, using data on government corruption in US states, we provide some new evidence that supports the theoretical findings
Complementarities, Coordination, and Culture
We develop a new model of the intergenerational transmission of culture based on the labor market characteristics of different cultural types. Following Borjas (1994,1995) we assume that cultural heterogeneity increases labor productivity due to skill complementarities, however following Jackson and Xing (2014) we also assume that cultural heterogeneity hampers com-munication. We model this as a game in which individuals first engage in uniformly random matching, and then once matched play a coordination game. Other-type matches are thus potentially more productive, but also less likely to coordinate. We show that this set up can replicate many of the seminal results of Bisin and Verdier (2001) without assuming imperfect empathy. This means that we do not face the inherent difficulties that such models involve when making welfare statements. Further, we are able to obtain new results concerning the efficient size of a cultural minority, the effects of tax and welfare programs on the size and welfare of minorities, and the relationship between the intensity of social interaction and size and welfare of a minority. In an extension of the model we introduce “intermediaries” who may either facilitate other-type matching or improve after-match coordination. We then ask which parent population, the minority or majority, the intermediaries arise from and explore their implications for the equilibrium and welfare
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Functional Brain Hyperactivations Are Linked to an Electrophysiological Measure of Slow Interhemispheric Transfer Time after Pediatric Moderate/Severe Traumatic Brain Injury.
Increased task-related blood oxygen level dependent (BOLD) activation is commonly observed in functional magnetic resonance imaging (fMRI) studies of moderate/severe traumatic brain injury (msTBI), but the functional relevance of these hyperactivations and how they are linked to more direct measures of neuronal function remain largely unknown. Here, we investigated how working memory load (WML)-dependent BOLD activation was related to an electrophysiological measure of interhemispheric transfer time (IHTT) in a sample of 18 msTBI patients and 26 demographically matched controls from the UCLA RAPBI (Recovery after Pediatric Brain Injury) study. In the context of highly similar fMRI task performance, a subgroup of TBI patients with slow IHTT had greater BOLD activation with higher WML than both healthy control children and a subgroup of msTBI patients with normal IHTT. Slower IHTT treated as a continuous variable was also associated with BOLD hyperactivation in the full TBI sample and in controls. Higher WML-dependent BOLD activation was related to better performance on a clinical cognitive performance index, an association that was more pronounced within the patient group with slow IHTT. Our previous work has shown that a subgroup of children with slow IHTT after pediatric msTBI has increased risk for poor white matter organization, long-term neurodegeneration, and poor cognitive outcome. BOLD hyperactivations after msTBI may reflect neuronal compensatory processes supporting higher-order capacity demanding cognitive functions in the context of inefficient neuronal transfer of information. The link between BOLD hyperactivations and slow IHTT adds to the multi-modal validation of this electrophysiological measure as a promising biomarker
Quantifying Variation across 16S rRNA Gene Sequencing Runs in Human Microbiome Studies
Recent microbiome research has incorporated a higher number of samples through more participants in a study, longitudinal studies, and metanalysis between studies. Physical limitations in a sequencing machine can result in samples spread across sequencing runs. Here we present the results of sequencing nearly 1000 16S rRNA gene sequences in fecal (stabilized and swab) and oral (swab) samples from multiple human microbiome studies and positive controls that were conducted with identical standard operating procedures. Sequencing was performed in the same center across 18 different runs. The simplified mock community showed limitations in accuracy, while precision (e.g., technical variation) was robust for the mock community and actual human positive control samples. Technical variation was the lowest for stabilized fecal samples, followed by fecal swab samples, and then oral swab samples. The order of technical variation stability was inverse of DNA concentrations (e.g., highest in stabilized fecal samples), highlighting the importance of DNA concentration in reproducibility and urging caution when analyzing low biomass samples. Coefficients of variation at the genus level also followed the same trend for lower variation with higher DNA concentrations. Technical variation across both sample types and the two human sampling locations was significantly less than the observed biological variation. Overall, this research providing comparisons between technical and biological variation, highlights the importance of using positive controls, and provides semi-quantified data to better understand variation introduced by sequencing runs
Genotypic Variation in a Foundation Tree (\u3ci\u3ePopulus tremula\u3c/i\u3e L.) Explains Community Structure of Associated Epiphytes
Community genetics hypothesizes that within a foundation species, the genotype of an individual significantly influences the assemblage of dependent organisms. To assess whether these intra-specific genetic effects are ecologically important, it is required to compare their impact on dependent organisms with that attributable to environmental variation experienced over relevant spatial scales. We assessed bark epiphytes on 27 aspen (Populus tremula L.) genotypes grown in a randomized experimental array at two contrasting sites spanning the environmental conditions from which the aspen genotypes were collected. We found that variation in aspen genotype significantly influenced bark epiphyte community composition, and to the same degree as environmental variation between the test sites. We conclude that maintaining genotypic diversity of foundation species may be crucial for conservation of associated biodiversity
Evolution of the Near-Infrared Tully-Fisher Relation: Constraints on the Relationship Between the Stellar and Total Masses of Disk Galaxies since z=1
Using a combination of Keck spectroscopy and near-infrared imaging, we
investigate the K-band and stellar mass Tully-Fisher relation for 101 disk
galaxies at 0.2 < z < 1.2, with the goal of placing the first observational
constraints on the assembly history of halo and stellar mass. Our main result
is a lack of evolution in either the K-band or stellar mass Tully-Fisher
relation from z = 0 - 1.2. Furthermore, although our sample is not
statistically complete, we consider it suitable for an initial investigation of
how the fraction of total mass that has condensed into stars is distributed
with both redshift and total halo mass. We calculate stellar masses from
optical and near-infrared photometry and total masses from maximum rotational
velocities and disk scale lengths, utilizing a range of model relationships
derived analytically and from simulations. We find that the stellar/total mass
distribution and stellar-mass Tully-Fisher relation for z > 0.7 disks is
similar to that at lower redshift, suggesting that baryonic mass is accreted by
disks along with dark matter at z < 1, and that disk galaxy formation at z < 1
is hierarchical in nature. We briefly discuss the evolutionary trends expected
in conventional structure formation models and the implications of extending
such a study to much larger samples.Comment: ApJ, in press, 9 page
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