8,001 research outputs found
Evaluating Pension Portability Reforms: The Tax Reform Act of 1986 as a Natural Experiment
This paper uses the Tax Reform Act of 1986 as a natural experiment to evaluate the job mobility response of prime-aged US employees participating in employer sponsored defined benefit pension plans to a reduction in the vesting period for pension rights accrual. We apply difference-in-differences methods using data from the Survey of Income and Program Participation to estimate the treatment impact of this policy change. We find that on average the reform had no significant effects on voluntary job mobility of the treated group. Our findings are robust to the use of different control groups and difference-in-differences estimators.Labour mobility, employer-provided pension plans, vesting, program evaluation, propensity score matching
Entangled states close to the maximally mixed state
We give improved upper bounds on the radius of the largest ball of separable
states of an m-qubit system around the maximally mixed state. The ratio between
the upper bound and the best known lower bound (Hildebrand, quant.ph/0601201)
thus shrinks to a constant c = \sqrt{34/27} ~ 1.122, as opposed to a term of
order \sqrt{m\log m} for the best upper bound known previously (Aubrun and
Szarek, quant.ph/0503221). We give concrete examples of separable states on the
boundary to entanglement which realize these upper bounds. As a by-product, we
compute the radii of the largest balls that fit into the projective tensor
product of four unit balls in R^3 and in the projective tensor product of an
arbitrary number of unit balls in R^n for n = 2,4,8.Comment: 11 pages; v2: n qubit case adde
The Portfolio Choices of Hispanic Couples
This paper analyzes the portfolio allocations of couple-headed, Hispanic families using Survey of Income and Program Participation (SIPP) data. Our results reveal that Hispanic couples as a group are less wealthy than otherwise similar white couples, although there is substantial variation across Hispanic-origin groups. Much of the disparity in portfolio choices of Hispanic relative to whites appears to stem from these lower wealth levels. Accounting for these wealth disparities, Hispanic couples hold less financial wealth, but more real estate and business equity than do white couples.portfolio choices; Hispanic
Portfolio Allocation in the Face of a Means-Tested Public Pension
Is there evidence that households adjust their asset portfolios just prior to retirement in response to a means-tested public pension? We address this question by estimating a system of asset equations constrained to add up to net worth. We find little evidence that in 2006 healthy households or couples responded to the incentives embedded in the means test determining pension eligibility by reallocating their assets. While there are some significant differences in asset portfolios associated with being near the income threshold, being of pensionable age, and being in poor health these differences are often only marginally significant, are not robust across time, and are not clearly consistent with the incentives inherent in the pension eligibility rules. In 2006, any behavioral response to the means test seems to occur among single pensioners in poor health. Comparison with 2002 results suggests the incentives to reallocate assets may have weakened over time.asset portfolios, means testing, public pension, household wealth
The Asset Portfolios of Native-born and Foreign-born Households
This paper analyses the net worth and asset portfolios of native- and foreign-born Australian families using HILDA (wave 2) data. Specifically, we estimate a system of asset equations with an adding-up constraint imposed to control for variation in householdsâ total net worth. Our results indicate that after accounting for differences in human capital and income levels, single immigrants have a wealth advantage of almost 150,000 less wealth on average than native-born couples. Relative to equally wealthy native-born couples, immigrant-only couples hold substantially more of their wealth in their homes and less in the form of vehicles and financial assets. mixed couples, on the other hand, allocate their wealth across assets in the same way as nativeborn couples.Wealth, immigrants, housing
The Wealth of Mexican Americans
This paper analyzes the sources of disparities in the relative wealth position of Mexican Americans. Results reveal that wealth gaps are in large part not the result of differences in conditional expected wealth functions. Similarly, income differentials are important, but do not play the primary role in explaining the gap in median net worth. As much or more of Mexican Americans' wealth disadvantage is attributable to the fact that these families have more young children and heads who are younger. Furthermore, Mexican Americans' low educational attainment has a direct effect in producing a wealth gap relative to other ethnic groups (even after differences in income are taken into account) though education does not significantly affect the nativity wealth gap. Finally, geographic concentration is generally unimportant, but does contribute to narrowing the wealth gap between wealthy Mexican Americans and their white and black counterparts.wealth; Mexican American
Portfolio Allocation in the Face of a Means-Tested Public Pension
Is there evidence that households adjust their asset portfolios just prior to retirement in response to a means-tested public pension? We address this question by estimating a system of asset equations constrained to add up to net worth. We find little evidence that in 2006 healthy households or couples responded to the incentives embedded in the means test determining pension eligibility by reallocating their assets. While there are some significant differences in asset portfolios associated with being near the income threshold, being of pensionable age, and being in poor health these differences are often only marginally significant, are not robust across time, and are not clearly consistent with the incentives inherent in the pension eligibility rules. In 2006, any behavioral response to the means test seems to occur among single pensioners in poor health. Comparison with 2002 results suggests the incentives to reallocate assets may have weakened over time.asset portfolios; means testing; public pension; household wealth
Impact wave deposits provide new constraints on the location of the K/T boundary impact
All available evidence is consistent with an impact into oceanic crust terminating the Cretaceous Period. Although much of this evidence is incompatible with an endogenic origin, some investigators still feel that a volcanic origin is possible for the Cretaceous/Tertiary (K/T) boundary clay layers. The commonly cited evidence for a large impact stems from delicate clay layers and their components and the impact site has not yet been found. Impact sites have been suggested all over the globe. The impact is felt to have occurred near North America by: the occurrence of a 2 cm thick ejecta layer only at North American locales, the global variation of shocked quartz grain sizes peaking in North America, the global variation of spinel compositions with most refractory compositions occurring in samples from the Pacific region and possibly uniquely severe plant extinctions in the North American region. The K/T boundary interval was investigated as preserved on the banks of the Brazos River, Texas. The K/T fireball and ejecta layers with associated geochemical anomalies were found interbedded with this sequence which apparently allows a temporal resolution 4 orders of magnitude greater than typical K/T boundary sections. A literature search reveals that such coarse deposits are widely preserved at the K/T boundary. Impact wave deposits have not been found elsewhere on the globe, suggesting the impact occurred between North and South America. The coarse deposits preserved in Deep Sea Drilling Project (DSDP) holes 151-3 suggest the impact occurred nearby. Subsequent tectonism has complicated the picture
Recommended from our members
Natural History Specimen Collections
The Fish Collection described in this document was transferred in 1992 to the Fish Collection of the University of Texas at Austin in Austin (at that time administratively in the Texas Memorial Museum, but at the time of publication of this digital version of the document it is one (https://biodiversity.utexas.edu/resources/collections/ichthyology) of the Biodiversity Collections in the University's Biodiversity Center (https://biodiversity.utexas.edu/). Thus, the data on the specimens in the Fish Collection described here are now included in the data published to GBIF (https://www.gbif.org/dataset/6080b6cc-1c24-41ff-ad7f-0ebe7b56f311) and other global biodiversity data aggregators by the UT Biodiversity Center's Fish Collection. The same data are also included in the Fishes of Texas Project (http://fishesoftexas.org - Hendrickson, Dean A., and Adam E. Cohen. 2015. âFishes of Texas Project Database (Version 2.0)â doi:10.17603/C3WC70).
Some of the UTMSI Fish Collection specimens remained at the UT Marine Science Insitute on long-term loan from 1992 until sometime in 2017 when the MSI disposed of all remaining specimens (including also Invertebrates). Some were disposed of by a professional HazMat company, but many were apparently taken to the Smithsonian Institution's (USNM) division of Invertebrate Biology. The fate of fish specimens, however, remains unresolved, but the Ichthyology Division at USNM had no knowledge of them at the time this report was archived here.
Dean A. Hendrickson, Curator of Ichthyology, UT Austin, May 1, 2019The University of Texas Marine Science Institute, Port Aransas Marine Laboratory, Natural History Collection of Marine Organisms was initiated in the mid-1940's. Since that time specimens have been added from studies in the Gulf of Mexico, associated estuaries, and marine-influenced terrestrial habitats, with emphasis on the Texas and Mexico coasts. These studies were the baseline surveys for this area and have resulted in the collection of valuable marine organisms. The collection now holds approximately 5,000 catalogued specimens including all forms of biota, vertebrates, invertebrates, algae and flowering plants.
The collection includes the marine fish and invertebrate specimens of the Texas Parks & Wildlife Department, incorporated into the UTMSI-PAML collection in 1976. This state collection, numbering 3,000, is composed primarily of Texas Gulf coast species of fish and invertebrates, representing baseline surveys conducted by the state fisheries biologists. With this collection are card catalogues by specimen number and phylogenetic order.
Other collections incorporated are those from R/V Oregon cruises (U.S. Fish & Wildlife Service, Bureau of Commercial Fisheries, exploratory fishing vessel), H. H. Hildebrand's faunal surveys of the brown and pink shrimp grounds , Whitten et al.'s faunal survey of Texas coast jetties , J. W. Hedgepethâs specimens collected during numerous faunal surveys, tide trap studies, and vegetation and algal surveys. Noteworthy studies from which specimens have been added to the collection are listed in Table 1.
The museum collection is housed in an air-conditioned building in a room specifically designed for this collection. The present facility contains 924 square feet with 1089 square feet of shelf space, which can be trebled to accommodate BLM collections. There are at present 32 1' x 12' shelves, totaling 384 square feet; 194 18" x 12-1/2" shelves, totaling 303 square feet; and 120 11-1/2" x 42" shelves, totaling 402 5 square feet.
The collection is a working museum open to the scientific community; specimens are available on loan to members of this community. Specimens may be used by visiting researchers, graduate-level students, professors, and classes. Attached is an invoice form, "Invoice of Specimens" - a standard form used for loan of collection items.
The Port Aransas Marine Laboratory is committed to the continuing curation of specimens and will continue to provide the supplies necessary to maintain the natural history specimen collections. The University of Texas Marine Science Institute, Port Aransas Marine Laboratory is willing to incorporate the Bureau of Land Management collection into its collection. Funding is requested from BLM to obtain and incorporate all archived BLM specimens from the S.T.O.C.S. survey into the collection.Integrative Biolog
The Asset Portfolios of Native-Born and Foreign-Born Households
This paper analyses the net worth and asset portfolios of native- and foreign-born Australian families using HILDA (wave 2) data. Specifically, we estimate a system of asset equations with an adding-up constraint imposed to control for variation in householdsâ total net worth. Our results indicate that after accounting for differences in human capital and income levels, single immigrants have a wealth advantage of almost 150,000 less wealth on average than native-born couples. Relative to equally wealthy native-born couples, immigrant-only couples hold substantially more of their wealth in their homes and less in the form of vehicles and financial assets. Mixed couples, on the other hand, allocate their wealth across assets in the same way as native-born couples.wealth, immigrants, housing
- âŠ