Single-year Data Research Articles

A low cosmic microwave background variance in the Wilkinson Microwave Anisotropy Probe data

We have estimated the cosmic microwave background (CMB) variance from the three-year Wilkinson Microwave Anisotropy Probe (WMAP) data, finding a value which is significantly lower than the one expected from Gaussian simulations using the WMAP best-fitting cosmological model, at a significance level of 98.7 per cent. This result is even more prominent if we consider only the North ecliptic hemisphere (99.8 per cent). Different analyses have been performed in order to identify a possible origin for this anomaly. In particular, we have studied the behaviour of single-radiometer and single-year data as well as the effect of residual foregrounds and 1/f noise, finding that none of these possibilities can explain the low value of the variance. We have also tested the effect of varying the cosmological parameters, finding that the estimated CMB variance tends to favour higher values of n S than the one of the WMAP best-fitting model. In addition, we have also tested the consistency between the estimated CMB variance and the actual measured CMB power spectrum of the WMAP data, finding a strong discrepancy. A possible interpretation of this result could be a deviation from Gaussianity and/or isotropy of the CMB.

Pervasive Liquidity Risk

While there is no equilibrium framework for defining liquidity risk per se, several plausible arguments suggest that liquidity risk is pervasive and thus may be priced. For example, market frictions increase the cost of hedging strategies requiring frequent portfolio rebalancing. Also, liquidity risk is likely to play a role whenever the market declines and investors are prevented from hedging via short positions. Using monthly return data from 1963-2000, and a broad set of test assets, we examine six candidate factor representations of aggregate liquidity risk, and test whether any one of these are priced. The results are interesting. First, with the surprising exception of the recent measure proposed by Pastor and Stambaugh (2001), liquidity factor shocks induce co-movements in individual stocks' liquidity measure (commonality in liquidity). The commonality is similar to that found in the extant literature (Chordia, Roll, and Subrahmanyam (2000)), which so far has been restricted to a single year of data. Second, again with the exception of the Pastor-Stambaugh measure, the liquidity factors receive statistically significant betas when added to the Fama-French model. Third, maximum-likelihood estimates of the risk premium are significant for the measure based on bid-ask spreads, contemporaneous turnover, as well as the Pastor-Stambaugh measure, which exploits price reversals following volume shocks. Overall, the simple-to-compute, low-minus-high turnover factor first proposed by Eckbo and Norli (2000) appears to do as least as well as the other factor measures.

Entrepreneurial global franchise ventures: US and European franchisee failure strategic and empirical perspectives

Rapid United States and European franchise growth offers potential benefits for stakeholders and host counties, as well as the potential for failure. Franchisee failure research is a complex area confounded by varying failure definitions, approaches, an event-focus, and single-year data. This paper includes a strategic franchisee failure perspective that views franchisee failure as a multi-stage process rather than an event; new longitudinal data from the United States for over 780 franchise systems and 292,000 franchise units and United Kingdom franchisee failure data for over 700 franchise systems and 31,000 franchisee units; and estimates of current European business-format franchise market size, including selected Central and Eastern European countries. Understanding and mitigating franchisee failure provide potential lessons for franchisors and franchisees. Franchisee failure and the strategic implications for franchise entrepreneurial ventures is a significant research area that merits further study and analysis.

From seasonal patterns to a reference situation in an estuarine environment: Example of the small fish and shrimp fauna of the Gironde estuary (SW France)

Detecting changes in animal communities suggests that a reference situation exists. It is a particularly difficult task in estuarine environments that are complex and fluctuate with time. Effects of human pressures are difficult to assess due to the scarcity or even the lack of evaluation and monitoring systems. In order to detect anomalies in the functioning of the system and to identify effects of perturbations upon populations and communities, it is necessary to analyse the dynamics in order to infer a reference state. This work aims to describe an approach based on K-Tab analyses and allows to define an average situation called “compromise” which is then compared to a single year of data. In this situation, the Gironde estuary, which has been monitored monthly from the 1980s, appears to be a very relevant case study. This paper focuses on spatial and temporal variations in species composition of fish and shrimp assemblages in the mesohaline and oligohaline stretches of the estuary and demonstrates a strong downstream-upstream structuring of species composition. Seasonal structure of the biological assemblages is highlighted and a biomass transfer in the water column between summer and winter is noticed. The habitat suitability is mainly discussed in terms of hydraulic regime but could also be discussed in terms of trophic resources availability. No important differences in the spatial distribution of the fish and shrimp assemblages can be detected between the year 2000 and the reference situation however the method is probably more relevant when detecting trends rather than single anomalies in the structure of the assemblages.

Comparison of small-area analysis techniques for estimating county-level outcomes

<h2>Abstract</h2><h3>Background</h3> Since many health data are unavailable at the county level, policymakers sometimes rely on state-level datasets to understand the health needs of their communities. This can be accomplished using small-area estimation techniques. However, it is unknown which small- area technique produces the most valid and precise results. <h3>Methods</h3> The reliability and accuracy of three methods used in small-area analyses were examined, including the synthetic method, spatial smoothing, and regression. To do this, severe work disability measures were first validated by comparing the 2000 Behavioral Risk Factor Surveillance System (BRFSS) and Census 2000 measures (used as the gold standard). The three small-area analysis methods were then applied to 2000 BRFSS data to examine how well each technique predicted county-level disability prevalence. <h3>Results</h3> The regression method produces the most valid and precise estimates of county-level disability prevalence over a large number of counties when a single year of data is used. <h3>Conclusions</h3> Local health departments and policymakers who need to track trends in behavioral risk factors and health status within their counties should utilize the regression method unless their county is large enough for direct estimation of the outcome of interest.

Prediction of Cultivar Performance Based on Single‐ versus Multiple‐Year Tests in Soybean

Because of the omnipresent genotype × year or genotype × location × year interactions in crop performance trials, it is commonly believed that multiple-year data should be used in selecting cultivars for the next year. An implicated but rarely tested hypothesis is that multiple-year data are more predictive than single-year data of cultivar performance in the next year. Yield data of the 1991 to 2000 Ontario Soybean Variety Trials in the 2800 Crop Heat Unit (CHU) area were used to study the power of single-year, multiple-location trials in predicting cultivar performances in the following year, and to see if data from multiple-year trials are more predictive. Mixed models were used to estimate best linear unbiased predictions (BLUP) of tested genotypes on the basis of single- or multiple-year trials, and the t-statistic of BLUP (tBLUP) was used as a measure of cultivar performance. Results indicated that a single-year, multiple-location trial had sufficient power for identifying genotypes that would perform well or poorly in the next year. Two to four years' data gave only slightly better predictions of next-year performances than single-year data but allowed more genotypes to be evaluated conclusively. The tBLUP of genotype effects based on 2 yr of multiple-location trials should be used as a basis for soybean cultivar selection and recommendation in the 2800 CHU area of Ontario.

Differences in Early Occupational Earnings of UK Male Graduates by Degree Subject: Evidence from the 1980-1993 Usr

This paper investigates the differences in early occupational earnings of UK male graduates by degree subject during the period 1980-1993. We match administrative student-level data from the Universities' Statistical Record (USR) and occupational earnings information from the New Earnings Survey (NES). The paper estimates relative earnings premia by degree subject using three alternative modelling approaches to control for student self-selection into university courses: i) a proxying and matching method, ii) a propensity score matching method, and iii) a simultaneous equations model of subject choice and earnings determination. Our analysis shows that there is a substantial amount of sample selection originating from unobservable student characteristics. The ranking of university subjects based on relative earnings premia is sensitive not only to the modelling approach but also to time, showing that analyses focusing on single-year data may not generalise to other periods.

Prediction of Cultivar Performance Based on Single- versus Multiple-Year Tests in Soybean

Because of the omnipresent genotype × year or genotype × location × year interactions in crop performance trials, it is commonly believed that multiple-year data should be used in selecting cultivars for the next year. An implicated but rarely tested hypothesis is that multiple-year data are more predictive than single-year data of cultivar performance in the next year. Yield data of the 1991 to 2000 Ontario Soybean Variety Trials in the 2800 Crop Heat Unit (CHU) area were used to study the power of single-year, multiple-location trials in predicting cultivar performances in the following year, and to see if data from multiple-year trials are more predictive. Mixed models were used to estimate best linear unbiased predictions (BLUP) of tested genotypes on the basis of single- or multiple-year trials, and the t-statistic of BLUP (tBLUP) was used as a measure of cultivar performance. Results indicated that a single-year, multiple-location trial had sufficient power for identifying genotypes that would perform well or poorly in the next year. Two to four years' data gave only slightly better predictions of next-year performances than single-year data but allowed more genotypes to be evaluated conclusively. The tBLUP of genotype effects based on 2 yr of multiple-location trials should be used as a basis for soybean cultivar selection and recommendation in the 2800 CHU area of Ontario.

Single-year data not enough

Australian and New Zealand Journal of Public HealthVolume 26, Issue 3 p. 278-279 Free to Read Single-year data not enough John Glover, Corresponding Author John Glover Public Health Information Development Unit, The University of Adelaide, South Australia PHIDU, 10 Pulteney Street, Adelaide South Australia 5001. Fax: (08) 8303 6240; e-mail: john.glover@adelaide.edu.auSearch for more papers by this authorSarah Tennant, Sarah Tennant Public Health Information Development Unit, The University of Adelaide, South AustraliaSearch for more papers by this author John Glover, Corresponding Author John Glover Public Health Information Development Unit, The University of Adelaide, South Australia PHIDU, 10 Pulteney Street, Adelaide South Australia 5001. Fax: (08) 8303 6240; e-mail: john.glover@adelaide.edu.auSearch for more papers by this authorSarah Tennant, Sarah Tennant Public Health Information Development Unit, The University of Adelaide, South AustraliaSearch for more papers by this author First published: 25 September 2007 https://doi.org/10.1111/j.1467-842X.2002.tb00689.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume26, Issue3June 2002Pages 278-279 RelatedInformation

Detecting tree populations at risk for forest conservation management: using single-year vs. long-term inventory data

We examined population dynamics of trees using 15 years inventory data (1984–1999) of a permanent plot in a Japanese temperate fir–hemlock forest to: (1) evaluate a method to predict tree species at risk of local extirpation using static, single-year data; and (2) quantify the risk of local extirpation for the declining species using the matrix model. Using data of the first year of inventory, tree species were categorized by the observed and expected size-class distributions into a 3×3 table. From the differences between the observed and expected distributions, 12 deciduous and one evergreen species, excluding pioneer species, were predicted as the risk group. With the long-term data (1984–1999), we stratified tree species into five groups based on estimated survival and recruitment rates, and the bottom group of five deciduous species were determined as the risk group. The single-year analysis worked marginally for detection of the risk group as well as species with poor survival, but significantly well to predict species with poor recruitment. These five groups were consolidated into the four groups based on Akaike’s information criterion (AIC), and the population densities of each group were simulated using the stochastic, density-dependent, 4-matrix model. The simulations predicted declines of deciduous species in general, and the lower two groups were likely to disappear from the plot in 400 and 70 years. However, total density of the forest was predicted to be maintained by compensatory growth of the upper two groups. The size-class analysis could be an easy and effective tool to detect species with poor recruitment for the conservation of fragmented forest patches.

Soil Nutrient Relationships with Topography as Influenced by Crop

Variable-rate fertilizer application is often based on grid soil sample data from a single year of data in an annual crop rotation. The objectives of this study were to determine if crop history influences spatial dependence (the degree of spatial variability) of nutrients in a rotation including both annual crops and alfalfa, and to compare grid-based and topography-based sampling strategies for representing within-field nutrient levels. A site in the Red River Valley of North Dakota was observed over three years from 1994–1996. The site was divided into one field of continuous alfalfa (Medica sativa L.) and an adjacent field seeded to spring wheat (Triticum aestivum L.) in 1994, barley (Hordeum vulgare L.) in 1995 and alfalfa in 1996. Samples were taken from a 16.2-ha site each fall in a 33-m grid and analyzed for NO3-N, P, SO4-S and Cl. Topography was determined by measuring elevation in a 33-m grid with a laser-surveying device. Spatial dependence was determined by calculating the semivariogram and using regression analysis to assess the relationship between the semivariogram and the semivariogram model. Spatial dependence of NO3-N and P was strongest following spring wheat and barley, while spatial dependence for SO4-S and C1 was strongest for vigorous stands of alfalfa. When the continuous alfalfa stand declined following winter kill, NO3-N and P spatial dependence intensified. Topography based sampling was correlated with the 33-m grid by giving each 33-m sampling location its value as directed by a topography sampling, then correlating that topography based value with the original 33-m sampling value. Topography-based sampling was correlated with the 33-m sampling grid for all nutrients following spring wheat and barley, but not in continuous alfalfa until the stand began to decline in vigor. Following alfalfa seeding in the annual crop field, topography relationships with NO3-N and P decreased, while topography relationships with SO4-S and Cl increased. Topography samplings of sulfate-S and chloride were most highly correlated to 33-m grid values in vigorous alfalfa. Lack of NO3-N spatial dependence in the vigorous alfalfa stands suggests that a composite or field average soil test might be sufficient to provide soil NO3-N information under similar conditions.

Patterns of Child Support Compliance in Wisconsin

This article examines 5-year compliance patterns among Wisconsin child support cases that came to court in 1986-1988. We find only limited support for the common assumption that compliance with child support orders declines over time. The average percentage paid is about .65 during each of the first 5 years following divorce or the establishment of paternity. One trend is an increasing polarization into groups of nonpayers and full payers. Although we find considerable stability from year to year among nonpayers (79% of nonpayers in one year do not pay in the following year) and full payers (84% of those who pay in full one year also pay in full the next), there is considerable change over the course of 5 years. Compliance during the first year provides some indication of long-term compliance, but about half of fathers change their compliance rate over the period. We find important differences between divorced and unmarried fathers, differences that are more pronounced than is apparent from a single year of data. Key Words: child support, compliance, single-parent families. Children living in single-parent families are economically vulnerable, with about half of such children living in poverty (U.S. Bureau of the Census, 1996). This economic insecurity and the increasing numbers of such children have triggered considerable interest in the effectiveness of the child support system. Researchers and policymakers widely acknowledge that low compliance with existing child support obligations is problematic. Nationally, approximately one half of resident parents with child support orders received the full amount due in 1991, one fourth received partial payments, and one fourth received nothing (U.S. Bureau of the Census 1995). Low annual compliance also has been documented in a variety of local and state studies (e.g., Bartfeld & Meyer, 1994; Meyer & Bartfeld, 1996; Peters, Argys, Maccoby, & Mnookin, 1993). Accordingly, numerous policy initiatives over the past two decades have attempted to increase rates of compliance. Such initiatives include intercepting income tax refunds of noncomplying, nonresident parents; placing liens on the property of delinquent obligors; and routinely withholding child support from the wages of parents with support orders. The most recent initiatives were part of the Personal Responsibility and Work Opportunities Reconciliation Act of 1996, which requires states to have legislation in place to rescind driver's licenses and professional licenses when nonresident parents become delinquent in their payments. Despite the consensus that child support compliance is inadequate, existing knowledge about long-term compliance is surprisingly limited. We know little about how aggregate compliance rates change between the early and later years of an order, and more important, we know little about how compliance changes from year to year at the individual level or how annual compliance compares with compliance over the longer term. Such information is critical both in defining the problem of low child support compliance and in designing appropriate interventions. This article begins to fill these gaps by presenting data on aggregate and micro-level patterns of compliance among divorced and unmarried fathers who have child support orders in Wisconsin. THEORY AND LITERATURE REVIEW Theoretical models of child support compliance typically posit that compliance is affected by the nonresident parent's ability to pay, by the economic needs of the resident parent, by the strength of the ties between the nonresident parent and his or her ex-partner and children, and by the stringency of the enforcement system. These models have been substantiated to varying degrees by empirical work examining the extent to which nonresident fathers comply with child support orders at a particular point in time. (See, for example, Meyer & Bartfeld, 1996; Peters et al., 1993. …

High-Precision Radiocarbon Age Calibration for Terrestrial and Marine Samples

Single-year and decadal radiocarbon tree-ring ages are tabulated and discussed in terms of 14C age calibration. The single-year data form the basis of a detailed 14C age calibration curve for the cal ad 1510–1954 interval (“cal” denotes calibrated). The Seattle decadal data set (back to 11,617 cal BP, with 0 BP = ad 1950) is a component of the integrated decadal INTCAL98 14C age curve (Stuiver et al. 1998). Atmospheric 14C ages can be transformed into 14C ages of the global ocean using a carbon reservoir model. INTCAL98 14C ages, used for these calculations, yield global ocean 14C ages differing slightly from previously published ones (Stuiver and Braziunas 1993b). We include discussions of offsets, error multipliers, regional 14C age differences and marine 14C age response to oceanic and atmospheric forcing.

Interannual Mixed Function Oxidase (MFO) Activity in Winter Flounder (Pleuronectes americanus) from a Coal Tar Contaminated Estuary

7-Ethoxyresorufin-O-deethylase (EROD), benzo[a]pyrene hydroxylase (BaPH), and cytochromes P-450 (cyt-P450) and b5(cyt-b5) varied annually in winter flounder (Pleuronectes americanus) collected in August of 1987, 1988, and 1989 from a coal tar contaminated estuary (Sydney, Nova Scotia, Canada). For August 1989, with fish available from all estuary areas, these indices correlated strongly with a spatial (along estuary) gradient in PAH in bottom sediments (7.19 ± 6.59–191 ± 184 μg g dry weight−1). Mean EROD activities in flounder near the coal tar source were up to seven times those in other estuary areas and paralleled sediment PAH loadings; however, standard deviations were high. Correlations for all MFO indices and sediment PAH were obtained in female flounder (P &lt; 0.01: EROD, cyt-b5, cyt-P450; P &lt; 0.02: BaPH). For male flounder the trend was similar, but only cyt-P450 correlated with sediment PAH (P &lt; 0.017). BaPH activity was highest near the coal tar source but was more variable and less sensitive to pollutant levels than EROD activity. Somatic indices in fish from Sydney estuary and St. George's Bay were similar. Winter flounder are vulnerable to PAH-induced MFO activities from coal tar contaminated sediments, but MFO induction does not occur equally in all fish; single-season or single-year data must be interpreted with caution.

A Demographic Decomposition of the Recent Increase in Crude Birth Rates in China

The triple standardization method was used to estimate the separate effect of changes in age structure marriage pattern and marital fertility on the crude birth rate in China. The decomposition method is described. Data were from the 1982 Census the 1987 1% Population Survey and the 1988 2/1000 Fertility and Contraceptive Survey. Single-year age data for 1981 and 1987 were estimated nationally and for each province based on the 1982 population census and life tables. Single-year ages of both sexes in 1984 were estimated from 1987 survey data and life tables. Age-specific fertility rates are given from the 1988 2/1000 Survey. The 1984 birth rate was computed separately and comparability with 1987 data was obtained by the same calculation. Discussed are 3 components of recent fertility change data methods and data sources 1981 and 1987 compared and 1987 and 1984 compared. It is concluded that changes in age structure and declining age at marriage are primarily responsible for the increase in the crude birth rate for the country as a whole and for most provinces. The increase in marital fertility is much less important. Chinas population growth is not considered in light of this study to the out of control again or to be a reversal of trends in marital fertility. Large birth cohorts in the 1960s entered their childbearing years in the 1980s. The New Marriage Law legalized a minimum age at marriage of 20 years instead of 23 years and this accounts for the declining age at marriage rather than a weakening of the family planning program in China. The civil registration of marriage data between 1984-87 had an impact of 5% on the crude birth rate in 1984 compared with an impact of 13.2% from age structure and 7.6% from marriage pattern. The small increase in marital fertility is explained by the relaxation of fertility control policies in rural areas to allow for a 2nd child with appropriate spacing. Compliance with the birth spacing policy was better in 1987 than in 1984 when the policy was introduced. Administrative decentralization has also loosened policy control. It is projected from the recent 1990 census that the number of women in the childbearing ages will be 322 million for each year between 1991-95 (an 8.1% increase over 1986-90 and a 16.2% increase in the peak childbearing years of 20-29). Promoting late marriage and late childbearing will help to curb population growth.

Lifelong Black-White Differences in Bone Size and Cortical Area

Sir .—It is a distinct pleasure to discover that Li et al 1 have been able to confirm our earlier findings on black-white differences in skeletal mass and volume even in the preschool years. Despite differences in technology (direct photon absorptiometry vs radio-grammetry), in anatomical site (forearm vs hand), and in the samples considered, we are in agreement that black children (like black adolescents and adults) have larger skeletal dimensions once birth differences are erased, and they have larger bone masses as well. 2-4 Since our sample of 1163 white children and 675 black children is considerable, it is possible to show how the relative magnitude of the differences increases from the first through the sixth year. Arranging our single-year data to agree with the 2-year age groupings used by Li et al, black-white differences in total bone width increased from 1% to more than 7% (Table). Differences in cortical

Estimates of stability for comparing varieties

For purposes of comparison of analytical methods the yield data on pearl millet hybrids and varieties for five years from locations in India and Pakistan have been analysed using a regression analysis and a meanstandard deviation analysis. The results of the mean-standard deviation analysis and the regression analysis were similar whether carried out on all environments, or on the highest- and lowest-yielding sets of environments. This was substantiated by the remarkable correlation between the slopes from the regression analysis and the standard deviations whatever environmental set was considered. The validity of using a single year's across location data with the mean-standard deviation analysis, if choice-theoretic criteria are used, was examined. It is concluded that, although further confirmation is required, single-year data seem to suffice. The relative merits of the mean-standard deviation analysis and a regression analysis are discussed; the choice-theoretic framework of the mean-standard deviation analysis is advantageous and complementary to the regression analysis.

Currents along the pacific coast of Canada

Abstract A series of oceanographic studies along the west coast of British Columbia in 1979–1982 produced several realizations of the seasonal cycle of currents. At one site, occupied for 3–1/4 years, the monthly mean currents are stable in speed and direction indicating that a single year of data reliably describes the pattern. Based upon three sets of observations at 15‐m depth (summer only) and 17 at 50‐m depth, the flow along Vancouver Island in winter is towards the northwest, parallel to shore, with some evidence that speeds are greater 15 km from shore (30–40 cm s−1) than farther offshore. In April the flow becomes more variable over the outer shelf a southeastward current develops near the shelf break in May, becoming strongest in August with speeds of 20 cm s−1. This southeastward flow appears to be a response to a shift to northerly winds in summer. Near shore during summer a flow tentatively labelled the Vancouver Island Coastal Current flows towards the northwest with speeds of 10–15 cms−1. By...

A high-precision calibration of the AD radiocarbon time scale

A high-precision calibration curve, derived from the radiocarbon age determinations of 195 decade samples spanning the AD 1 to 1950 interval, is presented.Though derived for the Pacific Northwest and California, the curve can be used for a large part of the northern hemisphere. This is proven by the radiocarbon ages of contemporaneous sample pairs which are, in most instances, identical within the quoted precision. Two sets of single-year data reveal no evidence for an 11-year cycle with an amplitude beyond the 12-year measuring precision. This indicates that the calibration curve is also applicable for single-year 14C samples.Analysis of the Seattle data sets and comparison with those published by the Belfast, La Jolla, and Heidelberg laboratories show that the total variability in a radiocarbon age determination is often larger than that predicted from the quoted errors. Upper limits for the error multiplier (ie, the factor with which the quoted error has to be multiplied to obtain the overall laboratory variability) are estimated at 1.5 for Seattle and Belfast, 1.1 to 1.4 for La Jolla, and 2.0 for Heidelberg.The comparisons with Belfast, La Jolla, and Heidelberg also reveal offsets with the Seattle calibration curve of, respectively, 4, 27 to 55, and 58 years. These offsets are most likely due to laboratory bias. An improvement of the present calibration curve by combining data sets from other laboratories will only be possible when offsets and error multipliers are precisely known through interlaboratory calibration.