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This article investigates the dynamics of the gender pay gap using an administrative dataset of Irish graduate earnings. Although male and female graduates have similar earnings initially, a substantial gap emerges in the 10 years after graduation. We focus on three possible sources: childbirth, field of study, and job mobility. We find that the gap is driven by the earnings of mothers, which fall by 24 per cent relative to trend immediately after childbirth and this effect is evident for all field groupings. We examine and dismiss the possibility that the gender difference is driven by job mobility; in fact, almost all the difference arises for job stayers. Although there is a large and persistent reduction in average hours of work after childbirth, this does not seem to explain all of the emerging gap. Our results suggest that policy measures should focus on earnings dynamics within firms.

Keywords: gender pay gap; motherhood penalty; field of study.

Bullying can occur at all ages and has been associated with several negative impacts on the psychological and emotional well-being of victims. While the transition to adulthood may be an opportunity for victims to escape bullying, prior research has suggested some continuity of victimisation experiences into adulthood. However, research on victimisation among young adults remains scarce and no prior study has examined this issue in the Irish context. Binary logistic regression was used to examine the likelihood of victimisation at age 20 based on the respondent’s prior victimisation history and other risk factors, using data from 4693 respondents in the Growing Up in Ireland National Longitudinal Study at age 9, 13, 17 and 20. Moreover, the risk of depression and levels of global self-esteem at age 20 were examined in terms of (long-term) victimisation experiences. Respondents who were previously victimised in adolescence and respondents who were chronically victimised in childhood and adolescence were approximately 3.5 and 4 times more likely to be victimised at age 20 respectively than respondents who were never victimised. The negative outcomes of victimisation regarding the risk of depression and lower levels of self-esteem were more severe for respondents who experienced more persistent prior victimisation. In conclusion, more persistent long-term victimisation experiences are associated with more severe negative outcomes and an increased risk of continued victimisation throughout the transition to adulthood compared to less persistent or no prior victimisation. Therefore, supporting affected individuals to escape victimisation as early as possible is crucial.

Technological advancement has seen a rise in computer-based and online gaming, and the online space has facilitated a proliferation in gambling options that increasingly adopt game-like features. There is a concern that gaming in childhood could predispose subsequent engagement with gambling behaviors, which has drawn the attention of parents, researchers, governments, and the European Union. To inform policy and legislation aimed at mitigating gambling-related harms, this research uses three waves of longitudinal data from Ireland to examine whether computer game engagement at 9-years-old (collected in 2007/8), and online gaming at 17 and 20, is associated with gambling participation in young adulthood. Multiple regression models, adjusting for a range of socio-economic and health characteristics, revealed that online gaming at 17 was associated with 1.4 higher odds of more frequent online gambling at 20 years (p = 0.011), while online gaming at 20 was associated with a 1.7 higher odds (p < 0.001). However, no association between early computer-based gaming at 9 years and subsequent gambling behaviors at 20 was uncovered for this cohort (born in 1998). Given more recent introductions of loot boxes and social casino games, continuous research is needed for future cohorts which may be greater affected by such developments.

Background
Early and risky adolescent alcohol use have each been associated with adult alcohol consumption. However, it remains unclear whether these behaviours independently predict later-life substance use when considered jointly, and research examining links with substances other than alcohol is limited. This study addresses these gaps by examining longitudinal associations between age at first alcohol and risky adolescent alcohol use, with alcohol, tobacco, cannabis and other drug use in early adulthood, and aims to identify critical periods for public health interventions.

Methods
Growing Up in Ireland is a nationally representative cohort (recruited aged 9 [Wave 1], born 1997–1998). Survey-weighted logistic regression examined whether age at first alcoholic drink and risky alcohol use at age 17 (Alcohol Use Disorders Identification Test scores) independently predict high-risk alcohol (AUDIT > 15), tobacco, cannabis and other drug use at age 20. Models were adjusted for age, sex, academic ability, personality, psychological factors, socioeconomic status, familial, peer and neighbourhood substance use.

Results
The study included 4554 participants (49.8% female). Early alcohol use was common, with 27% reporting use aged 14 or younger. By age 20, 14% reported high-risk alcohol, 38% tobacco, 24% cannabis and 28% other drug use. Older age at first alcohol was associated with dose-response reductions in the odds of high-risk alcohol, tobacco, cannabis and other drug use at age 20, relative to those initiating alcohol at 14 or younger. Adolescents with high-risk alcohol use had double the odds of tobacco (adjusted odds ratio (aOR) 2.1, 95% confidence intervals (CI) 1.3–3.30) and other drug use (aOR 2.5, 95% CI 1.6–4.1) and an 11-fold increase in the odds of continued high-risk alcohol use (aOR 11.5, 95% CI 7.0–18.6) at age 20, relative to adolescents with low-risk alcohol use.

Conclusions
Age at first alcohol and risky adolescent alcohol use independently predict substance use in early adulthood when considered jointly in extensively adjusted models. These findings highlight the continued urgent need for public health interventions that address factors associated with early alcohol use and support adolescents who use alcohol in a high-risk manner given their elevated risk of progression to more serious substance use as adults.

Background
Whether, and how, infant characteristics and parenting quality interact is one of developmental psychology’s key questions. However, whether specific interaction patterns replicate across cohorts or developmental outcomes is largely unknown. This study investigates whether infant characteristics and parenting quality are independent predictors (additive effects) of child outcomes or interact such that certain infants particularly suffer from poor parenting (diathesis stress), particularly benefit from good parenting (vantage sensitivity) or both (differential susceptibility).

Methods
Individual participant data from over 30,000 children from four prospective cohorts were pooled. Using a competitive-confirmatory approach of model evaluation, 16 possible permutations of infant characteristics (temperament and birthweight), parenting (maternal-reported stimulating and sensitive parenting) and later developmental outcomes (fluid and crystalised intelligence, internalising and externalising behaviour) were tested. The robustness of results was evaluated by subsequently varying analytic methods, using alternative parenting measures including observer reports and excluding covariates.

Results
AIC values in 10/16 analyses indicated infant characteristics acted independently of maternal-reported parenting for predicting developmental outcomes. Interaction patterns indicating diathesis stress (4/16), vantage sensitivity (2/16) or differential susceptibility (0/16) were rare or absent. However, diathesis-stress patterns were frequently found regarding birthweight and internalising behaviours, which were largely robust to methodological changes.

Conclusions
Developmental outcomes are more consistently explained by additive effects rather than by interaction effects.

This study uses high-quality longitudinal data from the Growing Up in Ireland study to examine the interplay between home learning environment (HLE) and early childhood education (ECE) in explaining children’s skills development from 9 months to 5 years old across parental socioeconomic status (SES). Random-effects linear regression models show that: (1) supportive HLE improves children’s cognitive and socioemotional skills and ECE quality critically fosters early socioemotional skills; (2) SES is associated with higher early cognitive and socioemotional outcomes, while responsive and consistent parenting behaviours among low-SES parents is particularly critical to improve their children’s socioemotional well-being; (3) high-quality ECE attendance compensates for children’s behavioural problems in less responsive parenting environments, especially among low-SES families, whereas home literacy stimulation is necessary condition for high-quality ECE attendance to benefit children’s early cognitive skills. Overall, HLE and ECE mutually interact in explaining differences in children’s early skills development across SES groups.

Lone mothers have been found to report lower average mental health than partnered mothers. Following the ‘stress process model’, disparities in women’s mental health by family structure could be explained by lone mothers’ higher exposure to multiple forms of stressors, compared to partnered mothers. Yet, this hypothesis has not been tested in previous studies. This study analysed four waves of longitudinal data from the Growing Up in Ireland study, spanning between the year when women gave birth (2008) to 9 years later (2017) (N = 5,654 women), to examine how family stressors (i.e., financial strain, caregiving strain, work-related strain, and parental conflict) influence mothers’ depressive symptoms by family structure. Analyses applied random-effects models and Karlson-Holm-Breen (KHB) decomposition techniques, combined with different model specifications as robustness checks (i.e., fixed-effects). Results indicate that: (1) net of sociodemographic factors, lone mothers experience higher levels of depressive symptoms than partnered mothers, with additional analyses confirming that transitioning from partnered to lone mother is associated with higher depressive symptoms, and from lone to partnered mother with reduced depressive symptoms; (2) although 41% of the observed statistical association between family structure and mothers’ depressive symptoms is direct, a larger 59% of this mental health gap is mediated by inequalities between lone and partnered mothers in their exposure to family stressors; and (3) the largest share of the observed mediation by family stressors is explained by lone mothers’ higher risks of current and past caregiving strain and parental conflict, but also by their current higher financial strain. Overall, this study suggests that lone mothers’ lower mental health, compared to partnered mothers, is largely explained by disparities in exposure to family stressors, pointing to how accumulated caregiving and parental stressors, as well as poverty risks, are key explanatory factors behind the mental well-being disadvantage that lone mothers face.

Adolescence and young adulthood are critical periods in the development of healthy sexual health and relationships, as patterns of behaviour that develop during these life stages shape outcomes throughout the life course. Recent rises in notifications of certain sexually transmitted infections (STIs) among young people in Ireland have raised concerns over the extent to which young people have the skills and information to make healthy choices in relation to their sexual health and wellbeing. In this context, sexual health literacy – i.e., the degree to which individuals have the ability to find, understand and use information and services to inform decisions and actions – is a key protective factor for the prevention of negative sexual health outcomes and for allowing young people to be more in control of their own sexual and reproductive health. In this report, we used data from Cohort ’98 of Growing Up in Ireland, the national longitudinal study of children and young people in Ireland, to examine the factors associated with sexual health literacy among young adults, and how sexual health literacy is associated with sexual health behaviours (i.e., condom and contraception use). The Growing Up in Ireland data on sexual health literacy were collected in 2018 when the young people were 20 years of age, and the measure of sexual health literacy was based on answers to two questions that gauged knowledge of female fertility and STI prevention methods.

Purpose
Despite growing concerns about trends in cocaine use, there is a shortage of longitudinal research that prospectively examines risk and protective factors associated with cocaine initiation and use in general youth populations. This study addresses this gap.

Methods
Growing Up in Ireland is a nationally representative cohort. Individual, family, and socio-environmental exposures associated with incident past-year cocaine use at ages 17 (N = 5965) and 20 (n = 4549) were assessed with survey-weighted logistic regression using generalised estimating equations. Prevalent past-year cocaine use at 20 (N = 4679) was analysed using generalised estimating equations complemented by gradient-boosted decision trees and Shapley explanations.

Results
221 (3.7%) self-reported cocaine use at 17 and 1072 (22.9%) at 20. Alcohol use at 14 or younger was associated with eight times the odds of cocaine use at 17 (aOR 8.0, 95% CI 1.7–37.3) and 19 times at 20 (aOR 19.2, 95% CI 8.6–43.2). Peer cannabis use was associated with 7 times the odds of cocaine use at 17 (aOR 7.3, 95% CI 2.9–18.3) and double at 20 (aOR 2.4, 95% CI 1.8–3.2). Growing up in a neighbourhood where substance use was common doubled the odds of cocaine use at 17 (aOR 2.4, 95% CI 1.3–4.4). Shapley explanations revealed individual-specific positive or negative impacts of exposures.

Discussion
Cocaine use among 20-year-olds in Ireland is higher than reported internationally, and increases sharply between the ages of 17 and 20, suggesting a need for interventions targeting this age group. However, associations with early adolescent factors suggest that early interventions may also be important.

The world-wide COVID-19 pandemic significantly disrupted education, with school closures leading to a shift to remote learning. Existing and emerging research has shown that even a relatively short period of missed school has negative consequences for academic and social outcomes among children and young people, especially for those from more vulnerable families. While emerging research drawing on cross-sectional data has focussed on how the pandemic has affected immigrant youth, there is a paucity of longitudinal studies in this field. In this paper, we used the longitudinal Growing Up in Ireland study to investigate and analyse the wellbeing of migrant-origin 12-year-olds in Ireland during the COVID-19 pandemic. Our research shows that compared to their Irish peers, immigrant adolescents had poorer wellbeing, partly related to differences in family support for remote learning, in experiences of poor-quality interaction with peers and in levels of family strain.