Age Cohort Analysis Research Articles

Revealing Cultural Dynamics in WAIS-IV Performance: a Comparative Analysis of Age Cohorts in Taiwanese and U.S. Populations.

This study examined the relationship between culture and cognitive abilities by comparing WAIS-IV subtests, index scores, and Full-Scale Intelligence Quotient (FSIQ) scores across various age groups in the Taiwanese and U.S. populations. The Taiwanese and U.S. versions of WAIS-IV are comprehensively compared, examining subtest items, psychometrics, and sample characteristics. Scaled scores are compared by extracting raw scores with a scaled score of 10 from each subtest scale in the Taiwanese version and applying U.S. age norms to acquire U.S. scaled scores. Despite the mean FSIQ score closely aligning with the U.S. sample, notable discrepancies are evident in the Taiwanese Verbal Comprehension Index (VCI) score, potentially influenced by cultural fairness of the tests. Significant variations are observed among age cohorts in the Taiwanese sample, with younger individuals excelling in Processing Speed Index, Working Memory Index, Perceptual Reasoning Index, and FSIQ, while maintaining comparable VCI scores to their U.S. counterparts. Conversely, older cohorts demonstrate lower performance across various domains, except for visuospatial reasoning and organizational skills, compared to their U.S. counterparts. These subtest variations robustly correlate with educational disparities between the Taiwanese and U.S. samples. Despite the similarity in factor structures between the Taiwanese and U.S. versions of WAIS-IV, this study reveals cultural bias in both verbal and non-verbal subtests. The study highlights the intricate interplay among cognitive processing styles, cultural influences, and educational factors contributing to performance disparities.

Mortality related to HCV and other chronic liver diseases in Veneto (Italy), 2008-2021: Changes in trends and age-period-cohort effects.

The objective of this study was to assess the impact of the COVID-19 pandemic and direct-acting antiviral (DAA) agents on mortality related to chronic liver diseases (CLD). Age-standardized mortality rates were computed based on CLD as the underlying cause of death (UCOD) and as any mention in death certificates (multiple causes of death-MCOD). Time trends in age-standardized mortality rates were investigated using generalized estimation equation models. Additionally, we conducted age, period, and birth cohort (APC) analyses on CLD-related mortality associated with alcohol and hepatitis C virus (HCV). Between 2008 and 2021, among residents in the Veneto region (Northeastern Italy) aged ≥35 years, there were 20 409 deaths based on the UCOD and 30 069 deaths based on MCOD from all CLD. We observed a 4% annual decline in age-standardized MCOD-based mortality throughout 2008-2021, with minor peaks corresponding to COVID-19 epidemic waves. Starting in 2016, the decline in HCV-related mortality accelerated further (p < .001). A peak in HCV-related mortality in the 1963-1967 birth cohort was observed, which levelled off by the end of the study period. Mortality related to alcoholic liver disease declined at a slower pace, becoming the most common aetiology mentioned in death certificates. The study demonstrates a significant decrease in HCV-related mortality at the population level in Italy with the introduction of DAAs. Continuous monitoring of MCOD data is warranted to determine if this favourable trend will continue. Further studies utilizing additional health records are needed to clarify the role of other CLD etiologies.

Transition in Primary and Secondary Schooling in Pakistan: Gender and Age Cohort Analysis

This study assesses the changing pattern of school attendance through age cohort analysis for both males and females in Pakistan. Based on the 1998 census data on educational attainment, the results indicate a profound rise in school attendance among younger age cohorts contributing to elimination of gender gap in primary-level schooling in urban areas only. The disadvantaged situation of rural females is reflected by a combination of low school entries/attendance to begin with, and high chance of discontinuing education before completing primary levels. The pattern of school transition reveals that among those few who have completed Class Five, the chances of staying through the secondary level are much higher—after which dropout accelerates rapidly. Two overall conclusions emerge from these results. First, the bulk of the deficit from universal primary education comes from females population, especially in rural areas. Second, the key to reducing dropouts and gender gap in school attendance lies in actions that raise the demand for schooling of girls, with equally matched availability of quality primary- and secondarylevel schools. It appears that achieving universal primary education by 2015, as mandated in the Millennium Development Goals (MDGs), remains a tall order for Pakistan.

Large-scale network connectivity as a predictor of age: Evidence across the adult lifespan from the Cam-CAN data set.

Changes in brain connectivity patterns as a function of age have been recently proposed to underlie differences in cognitive abilities between young and older adults. These shifts track patterns of increased functional coupling between the executive control network (ECN)-a network of prefrontal and parietal areas that is broadly implicated in externally directed attention and cognitive control-and default mode network (DMN) regions-most commonly associated with internally directed cognitive activity. Although age-related changes in ECN-DMN coupling are well characterized, the contributions of the salience network are less clear. Furthermore, given the salience network's crucial role in arbitrating ECN-DMN functional connectivity, it is important to understand its contribution throughout the adult lifespan. Here, we used the data from a large cohort (N = 547) of participants from the Cambridge Centre for Ageing and Neuroscience (Cam-CAN) database (18-88 years old) to investigate first whether resting-state ECN-DMN functional connectivity predicts age. We further examined how connectivity between ECN, DMN, and salience network regions impacts the hypothesized age-related increased connectivity between ECN and DMN areas. Multiple regression analyses revealed that connectivity between dorsolateral and ventromedial prefrontal cortex and parietal regions, including the precuneus, accounted for a significant portion of age variability and that the inclusion of connectivity between orbitofrontal insula, anterior insula, and anterior cingulate regions of the salience network improved the models' explanatory power. Additional age cohort analyses further highlighted that these relationships vary across the lifespan. We discuss how these findings expand on our current understanding of the variations in large-scale intrinsic network connectivity as a function of healthy aging. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Equity Mutual Funds in Healthcare Sector: A Comparison of Performance and Risk Through an Age-Cohort Analysis

Equity Mutual Funds in Healthcare Sector: A Comparison of Performance and Risk Through an Age-Cohort Analysis

Returns to formal and informal vocational education and training in India

PurposeIn the process of school-to-work transition, the role of general education and vocational education and training (VET) remains quite central. Based on the human capital theory, we estimate whether investment in VET brings additional returns for workers across the age cohorts.Design/methodology/approachThe focus of our study being the labour market in India, the data from the Periodic Labour Force Survey 2018–19, conducted by the National Statistical Office, has been used for analysis. We have applied the ordinary least square method with sample selection correction, the quasi-experimental technique of propensity score matching and heteroskedasticity based instrumental variable approach to estimate the returns with respect to no VET, formal VET and informal VET.FindingsOur study shows that workers with formal VET earn higher wages than workers with no VET or informal VET. The study finds that workers with informal VET do not earn higher wages than workers with no VET. Moreover, from the age cohort analysis, we have deduced that wage advantage of workers with formal VET persists across all age cohorts and, in fact, accentuates with an increase in age.Originality/valueWe have estimated that VET being complemented with basic general education fetches higher returns in the labour market, especially when provided through formal channels. Moreover, to the best of our knowledge, in the case of developing countries where informal VET is widely provided, this is one of the first studies that captures the return to informal VET. Lastly, complementing the existing studies on the developed countries, we have estimated the returns to VET over the life cycle of the workers.

Inequality in hospitalization due to non-communicable diseases in Sweden: Age-cohort analysis of the Uppsala Birth Cohort Multigenerational Study.

We aimed to investigate cohort differences in age trajectories of hospitalization due to non-communicable conditions, and if these varied by paternal socioeconomic position. We used the Uppsala Birth Cohort Multigenerational Study—including virtually complete information on medical diagnoses.Our sample constituted 28,448 individuals (103,262 observations). The outcome was five-year prevalence of hospitalization due to major non-communicable conditions in 1989–2008. The exposures were age (19–91), year-of-birth (1915–1929; 1938–1972), gender (man vs woman), and parental socioeconomic position (low, medium, and high). We used multilevel logit models to examine associations between exposures and the hospitalization outcome.Younger cohorts had a higher prevalence of hospitalization at overlapping ages than those born earlier, with inter-cohort differences emerging from early-adulthood and increasing with age. For instance, at age 40 predicted probability of hospitalization increased across birth-cohorts—from 1.2% (born in 1948-52) to 2.0% (born in 1963-67)—whereas at age 50 it was 2.9% for those born in 1938-42 compared with 4.6% among participants born in 1953-57. Those with medium and low socioeconomic position had 13.0% and 20.0% higher odds of experiencing hospitalization during the observation period, respectively—when age, year-of-birth and gender were accounted for.We found that no progress was made in reducing the socioeconomic inequalities in hospitalization across cohorts born between 1915 and 1972. Hence, more effective policies and interventions are needed to reduce the overall burden of morbidity—particularly among the most vulnerable.

Land reform and human capital development: Evidence from Peru

The early establishment and persistence of landholding inequality is linked to poor long-run development outcomes. One crucial channel runs through human capital: large landowners historically underinvested in public goods such as schools, restricted workers and their children from to attending school, and extracted surplus from laborers that could have been invested in human capital. By equalizing landholdings, land redistribution should facilitate human capital accumulation. Using original data on land reform across Peru in the 1970s paired with household surveys, we conduct an age cohort analysis and find instead that higher exposure to land reform negatively impacted educational attainment as measured by the number of years of school attended. The driving mechanisms appear to be economic opportunity as well as income and child labor: individuals exposed to land reform are more likely to remain in rural areas and to have their children contribute labor to agriculture, driving down income in the long term.

Are French millenials less car-oriented? Literature review and empirical findings

Generation effects play a key role in shaping long-term trends in travel behaviors. Though cohorts born until the 1970s have been increasingly car-focused, a reversal of this trend was noticed among the millenials. Determining whether this break-in-trend resulted from changes in living conditions and economic difficulties, or demonstrates a shift in attitudes away from the car, is critical to future travel trends. We bring a contribution to this debate in the French context, through a literature review followed by empirical findings, using the French Base of Local Household Travel Surveys. Through age-cohort analysis, we find evidence of changing travel patterns among the millenials, taking the form of a shift from driving to transit, along with a decline of car ownership. However, travel attitudes of the millenials play little role, as they do not differ substantially from their elders. Besides, we show that generation effects disappear once a large number of structural factors are controlled for. It looks like the main driver of change in travel behaviors comes from a shift in residential patterns, in relation with longer studies and a delayed entrance into the workforce, and possibly because of increasing work pressure, degraded transport conditions and changes in residential attitudes and desired lifestyles. In the end, these assumptions should be further explored, along with complementary research tracks, including the role of economic factors, the effects of learning experience, as well as heterogeneity in travel patterns, in relation with issues of social and spatial equity.

Global patterns and trends in ovarian cancer incidence: age, period and birth cohort analysis

BackgroundOvarian cancer (OC) is the seventh most common malignancy worldwide and the most lethal gynaecological malignancy. We aimed to explore global geographical patterns and temporal trends from 1973 to 2015 for 41 countries in OC incidence and especially to analyse the birth cohort effect to gain further insight into the underlying causal factors of OC and identify countries with increasing risk of OC.MethodsOC data were drawn from the Cancer Incidence in Five Continents databases and online databases published by governments. The joinpoint regression model was applied to detect changes in OC trends. The age–period–cohort model was applied to explore age and birth cohort effects.ResultsThe age-standardized rate of OC incidence ranged from 3.0 to 11.4 per 100,000 women worldwide in 2012. The highest age-standardized rate was observed in Central and Eastern Europe, with 11.4 per 100,000 women in 2012. For the most recent 10-year period, the increasing trends were mainly observed in Central and South America, Asia and Central and Eastern Europe. The largest significant increase was observed in Brazil, with an average annual percentage change of 4.4%. For recent birth cohorts, cohort-specific increases in risk were pronounced in Estonia, Finland, Iceland, Lithuania, the United Kingdom, Germany, the Netherlands, Italy, Malta, Slovenia, Bulgaria, Russia, Australia, New Zealand, Brazil, Costa Rica, Ecuador, India, Japan, the Philippines and Thailand.ConclusionsDisparities in the incidence and risk of OC persist worldwide. The increased risk of birth cohort in OC incidence was observed for most countries in Asia, Central and Eastern Europe, and Central and South America. The reason for the increasing OC risk for recent birth cohorts in these countries should be investigated with further epidemiology studies.

A study on mortgage loan borrowing behavior of Korean households : A micro perspective

This paper examines Korean household's borrowing behavior and the causes of default using granular data. It tries to establish a set of models that determine the original amount and delinquency of loans, using as independent variables financial and non-financial factors extracted from individual accounts and regulatory factors such as macroprudential tools. Our empirical findings suggest several meaningful implications. First, the application of LTV and DTI regulations at the date of borrowing turns out to be very effective in reducing the amount of loans and household's leverage (loan-to-income ratio or loan-to-collateral ratio) and also in mitigating defaults. Second, it is found that changes in housing prices are closely related to the loan size and its delinquency. A rise in housing prices drives up borrowings due to household's affirmative attitude. Conversely, their downturn has a negative impact on the soundness of existing loans, heightening the motive for strategically defaulting, notably when the auction price of a collateral house is below its loan balance. Recently, loan demand has become less sensitive to interest rates due to the upsurge in borrowings for daily living expenses and business funds. Lastly, our vintage and age cohort analyses show that there are relatively higher default risks in loans extended during the period of steeply rising housing prices and in those of seniors whose loan-to-income ratios are much higher.

Niche level segmentation of green consumers

PurposeThe purpose of this paper is to find the niche segmentation of green consumers as a solution to psychographic or demographic predicament. Age cohort and generational cohort (Gen Y and Gen Z) of young consumers are studied for individualization and customization.Design/methodology/approachAge cohorts (Gen Z and Gen Y customers) have their unique needs. Both Gen Y (1981-1995) and Gen Z (post-1995) belong to the young consumer segment in the age group of 20-30 years but their generational cohorts are different. Strategic marketing advocates both generational marketing based on age cohorts and segmented marketing for young consumers. Strategic marketing faces cross-road between youth segmentation and generational cohort (Gen Z and Gen Y) due to intersection between the two during the 20-30 age group. Primary data using the ecological conscious consumer behavior (ECCB) scale was collected and analyzed for understanding the individual and relative importance of psychographic and demographic factors in influencing green behavior. The traditional youth segment is sliced into four sub-groups (Young Nest 1-4), and their interaction effect with post hoc analysis was done for the identification of sources of difference between different age cohorts. The findings of the study were compared with previous studies and unique contributions of this study were identified.FindingsThe findings indicate multiple niche young segments with demographic as the primary criterion and psychographic as the building block. Niche level and individual level segments emerge due to the interaction of various factors within a given age cohort. The findings confirm the identity development process which considered age as an important factor that affects varying choices throughout life from adolescence to adulthood.Practical implicationsThe findings of this study may be used for effective targeting and positioning strategy of green marketing. In the time of analytics, age cohorts and generational cohort of young consumers can be approached differently for yielding better environmental results. The magnified niche level segmentation of young consumers may be used to develop individualized and customized promotions for young customers in Young Nest 1-4 for an enhanced ECCB.Originality/valuePrevious studies have focused more on consumer characteristics (demographic or psychographic) and their relative importance but niche level segmentation within given demographic segment was not attempted before. This study is unique in offering microscopic analysis of age cohorts of young consumers (Young Nest 1-4) and their interaction with other demographic variables (gender and income) for niche level segmentation.

Literacy achievement in India: A demographic evaluation

This article evaluates the progress in literacy among the Indian states, from an age-cohort perspective. It argues that age-cohort analysis offers a robust understanding of the dynamics of literacy progress. The article clearly brings out the fact that, despite the accomplishment of universal elementary education, achieving the goal of full literacy is quite difficult, owing to the existence of an out-of-school-age illiterate population. Thus, the study suggests provision of an effective adult-literacy programme along with universal elementary education in order to realize the goal of full literacy. Further, it argues that comparisons based on the average literacy rate have led to a computation of a “literacy deprivation index” adjusted with age structure—and that such adjustment leads us to view the literacy gap across all the states as wider, given that it assumes lower values. This minimal standardization, along with the age structure of the population, offers a valid comparison of this commonly used indicator. Its prospect of progress, too, is largely dependent upon the emerging age structure of the population as a result of the unfolding demographic transition.

Global patterns and trends in stomach cancer incidence: Age, period and birth cohort analysis.

The cases of stomach cancer (SC) incidence are increasing per year and the SC burden has remained very high in some countries. We aimed to evaluate the global geographical variation in SC incidence and temporal trends from 1978 to 2007, with an emphasis on the effect of birth cohort. Joinpoint regression and age-period-cohort model were applied. From 2003 to 2007, male rate were 1.5- to 3-fold higher than female in all countries. Rates were highest in Eastern Asian and South American countries. Except for Uganda, all countries showed favorable trends. Pronounced cohort-specific increases in risk for recent birth cohorts were seen in Brazil, Colombia, Iceland, New Zealand, Norway, Uganda and US white people for males and in Australia, Brazil, Colombia, Costa Rica, Czech Republic, Ecuador, Iceland, India, Malta, New Zealand, Norway, Switzerland, United Kingdom, Uganda, US black and white people for females. The cohort-specific ratio for male significantly decreased in Japan, Malta and Spain for cohorts born since 1950 and in Austria, China, Croatia, Ecuador, Russia, Switzerland and Thailand for cohorts born since 1960 and for female in Japan for cohorts born since 1950 and in Canada, China, Croatia, Latvia, Russia and Thailand for cohorts born since 1960. Disparities in incidence and carcinogenic risk persist worldwide. The favorable trends may be due to changes in environmental exposure and lifestyle, including decreased Helicobacter pylori prevalence, increased intake of fresh fruits and vegetables, the availability of refrigeration and decreased intake of salted and preserved food and smoking prevalence.

Generational analysis of trends in unprotected sex in France among men who have sex with men: The major role of context-driven evolving patterns.

ObjectiveUsing a generational approach, this study analyses how unprotected anal intercourse has evolved since 1991 in France across different generations of men who have sex with men (MSM) whose sexual lives began at different periods in the history of the HIV epidemic.DesignData were collected from 18–59 year-old respondents to the French Gay Press surveys Enquêtes Presse Gay, conducted repeatedly between 1991 and 2011 (N = 32,196) using self-administered questionnaires distributed in gay magazines and over the internet.MethodsTrends in unprotected anal intercourse (i.e. condomless anal sex) with casual partners of unknown or different HIV serostatus (hereafter “UAId” in this manuscript) were studied. Responses were analysed according to year and then reorganised for age-cohort analyses by generation, based on the year respondents turned 18.ResultsUAId rates fell from 1991 to 1997, and then rose from 13.4% in 1997 to 25.5% in 2011 among seronegative respondents, and from 24.8% to 63.3%, respectively, among seropositive respondents. Both in seropositive and seronegative respondents, UAId increased over time for all generations, indicative of a strong period effect.ConclusionAnalyses of data from several generations of MSM who started their sexual lives at different time points in the HIV epidemic, revealed very similar trends in UAId between generations, among both seropositive and seronegative respondents. This strong period effect suggests that sexual behaviours in MSM are influenced more by contextual than generational factors. The fact that prevention practices are simultaneously observed in different generations and that there are most likely underlying prevention norms among MSM, suggests that PrEP could become widely accepted by all generations of MSM exposed to the risk of HIV.

The New Understandings of Intergenrational Participation in Economic Activities in Korea

최근 세계적 경제 불황과 함께 국내에서는 청년실업 문제가 심각하게 대두되고 있다. 세대 간 고용과 실업에서의 균형 달성이 사회통합에 이바지한다는 가정 하에 세대 간 노동참여의 불평등을 진단하였다. 남녀표본과 전체표본을 대상으로 세대효과, 연령효과, 시대효과의 지속성 여부를 분석하기 위해 이력효과를 검증하였다. 정부의 가족정책이 산아제한에서 적극적 출산으로 변화되어 노동시장의 인구구성비의 변화가 효과를 지니는지를 살펴보고자 생산가능인구가 포함되거나 제외된 모형을 이용하였다. 1989~2014년까지 25년간 종단적자료를 이용하여 세대분석(Age Cohort Analysis)을 실시하였다. 고용률과 실업률에 대해 분석한 결과, 전체표본이든 남녀표본이든 연령효과, 시대효과, 세대효과가 모두 통계적으로 유의미하였다. 고용과 실업에의 영향력은 연령효과가 가장 크며 시대효과, 세대효과 순으로 나타났다. 최근으로 올수록 총 경제활동인구 중 30세 미만의 청년층 비중보다 상대적으로 60세 이상의 노인비중이 커지면서 노소 간 일자리 경쟁의 가능성이 나타났다. 이력효과에 대한 분석 결과, 남성의 경우 나이 든 세대집단일수록 고용과 실업이 높아지는 추세이다. 반면, 여성은 연령증가에 따라 고용과 실업 모두 낮은 수준에서 안정되는 경향이 있다. 생산가능인구가 증가함에 따라 1954년 세대집단부터 1979년 세대집단은 고용이 더 늘어났으며, 최근 세대인 1984~1989년 세대집단의 실업률은 증가하였다. 따라서 노년인구층이 두터워짐으로 인해 중년층이 아닌 젊은 청년층의 일자리가 줄어드는 효과가 나타나 이에 대한 정부 대책이 필요하다. 아울러 20대 초반에 고용이 일시적으로 강하지만 그 이후에 지속되는 여성의 저고용률에 대한 대책 마련이 절실한 것으로 분석되었다.The paper tries to study the intergeneratioal trend of economic activities participation, given that youth unemployment became a societal issue under economic stress. Provided that employment equality among generations contributes social integration, the study examines if there is an unbalance of the employment. By using Age-Period-Cohort Analysis with Hysteresis Effect, three sample groups of 25-year long data such as total sample, man sample, and woman sample group are empirically tested. The effects on the employment rates and unemployment rates reveal that the three effects, or age effects, year effects and cohort effects are statistically significant. The magnitude of the effects is age effects, year effects, and cohort effects in order from the top to the bottom. There has been the job conflicts between the aged generation aged 65 over and the youth generation aged under 30. Man workers are more likely to be layed off as they get older, while woman workers are not. The model with a control variable of workforce indicates that an increase in the workforce raises more employment for the cohort from 1954 to 1989, while the rise makes unemployment worse for the cohort from 1984 to 1989. There is a clear indication that, as older workers increase in labor market, younger workers experience the reduced number of jobs. Korea government needs to intervene the youth participation reduction in economic activities and especially the low employment for younger women.

Consumer Ethnocentrism and Influence of Role Model on Generational Cohorts’ Purchase Intentions towards Herbal Products

Purpose: The main purpose of this study was to investigate what leads customers to ethnocentrism and the effects of ethnocentrism on their attitudes towards purchase intentions. The other objective was to study product preferences of different age cohorts towards herbal products and the influence of role model on their purchase intention behaviours. Research methodology: Results are derived from primary data collected from a customer sample in New Delhi, India during the months of May–June, 2015. Data analysis was done using Statistical package for the social sciences (SPSS), version 20. Findings: This article identified that consumer ethnocentrism level differs according to age cohorts. For Baby Boomers and Generation X cohort, multiple linear regression analysis inferred that consumer ethnocentrism was the best predictor of purchase intention behaviour. In the case of Generation Y cohort, indirect role model, direct role model and consumer ethnocentrism did not significantly contribute to the purchase intention of Generation Y cohort. Practical implications: The research finding will be very useful in providing insight into Indian herbal product marketers to devise marketing strategies. The article contributes to research on consumer ethnocentrism by confirming some of the earlier findings with the help of a consumer sample from northern India. Contributions: This research study contributes to the existing literature by analysing the impact of consumer ethnocentrism and role model influence on purchase intention of customers on a diverse range of herbal product categories, using an age-cohort analysis. Research limitations: Consumers were asked to evaluate the attributes of herbal products without reference to any specific company/brand, and this could be one of the limitations of the study.

Steroids after the Kasai procedure for biliary atresia: the effect of age at Kasai portoenterostomy.

The use of adjuvant steroids following Kasai porteoenterostomy (KPE) for biliary atresia is controversial. The aim of this study was twofold: a systematic review of published literature and an update of the clinical Kings College Hospital series to look for evidence of an effect of age on the outcome in a group of BA infants treated with high-dose steroids. This clinical study included infants treated between January 2006 and June 2014 who underwent KPE by day 70 of life and who received high-dose steroids (oral prednisolone starting 5 mg/kg/day). They were subdivided into cohorts according to age at which KPE was performed. The outcome measured was clearance of jaundice (<20 µmol/L) by 6 months and native liver survival. R × C χ2 analysis and log-rank tests were used, respectively, and P ≤ 0.05 was regarded as significant. 104 infants were included with a median age at KPE of 45 (range 12–70) days. 71/104 (67 %) cleared their jaundice by 6 months of age. Age-cohort analysis showed a trend (P = 0.03) favouring early KPE (e.g. 100 % of 11 infants operated on <30 days clearing their jaundice compared to 66 % of those operated on between 61 and 70 days). There was a significant native liver survival benefit for those operated on <45 days (5 year NLS estimate 69 versus 46 %; P = 0.05). Clearance of jaundice is related to the age at KPE in infants who receive high-dose steroids. Native liver survival appears to be improved as a result of this. This is the first study to show tangible longer-term benefit from high-dose steroids in biliary atresia.

Nature and determinants of household retirement savings behaviour in South Africa

This study investigates the savings behaviour among South African households using the General Household Survey data for the periods 2002–04 and 2008–10. The age-cohort analysis shows that households achieve their income peaks when the household heads are in their early forties, earlier than in most other countries. Although initial support for the life-cycle hypothesis framework in the form of smoothed consumption was found from multivariate analysis, a closer examination reveals that the consumption–income ratio is also smooth over the age and cohort variables. This indicates that savings rates do not follow a hump-shape pattern as required in the life-cycle hypothesis framework. While households are seen to be able to maintain their consumption in retirement years through government grants, a large portion of the grants seem to be utilised for savings. This shows that the government grants have the dual effect of sustaining consumption levels while disincentivising savings during working years.

Moderate establishment success of Pacific oyster, Crassostrea gigas, on a sheltered intertidal mussel bed

The Pacific oyster (Crassostrea gigas Thunberg 1793) is introduced into marine ecosystems worldwide. In Denmark, C. gigas was introduced into the micro tidal Limfjord, around 1972 for aquaculture. This study describes the population structure of C. gigas at Agger Tange in 2007, 2009, 2010 and 2011. Here, C. gigas use beds of Blue mussels (Mytilus edulis L.) as primary habitat. The mean abundance (±1 SD) of C. gigas was unchanged during our study (45±2indv.m−2), while it increased for M. edulis from 2010 to 2011 (934±610 to 1434±750indv.m−2, respectively). In 2009, a newly settled cohort of C. gigas was present, but in the succeeding years no or negligible recruitment was recorded. However, age cohort analyses, based on individual shell size at different ages, suggest successful recruitment in three out of seven years. A comparison with the course of the bioinvasion in List Tidal Basin, suggests that the population at Agger Tange is not in the expansion phase of the bioinvasion, despite of frequent settlement, high shell growth rates and relatively high abundance. So far, C. gigas has had moderate establishment success. We conclude that C. gigas is still in the establishment phase, but that this is prolonged, presumably due to low food availability.