Background and aims: Diversion of opioid substitution drugs (OSD) is of public concern. This study examined the prevalence, frequency, and predictors of illicit OSD use in a group of injecting drug users (IDUs) and assessed if such use was associated with non-fatal overdoses.Methods: Semi-annual cross-sectional interviews conducted in Oslo, Norway, (2006Norway, ( -2013, from 1,355 street-recruited IDUs. Hurdle, logistic, and multinomial regression models were employed.Results: Overall, 27% reported illicit OSD use in the past four weeks; 16.8% methadone, 12.5% buprenorphine, and 2.9% both drugs. Almost 1/10 reported at least one non-fatal overdose in the past four weeks, and roughly 1/3 reported such experience in the past year. Use of additional drugs tended to be equally, or more prevalent among illicit OSD users than other IDUs. In terms of illicit OSD use being a risk factor for non-lethal overdoses, our results showed significant associations only for infrequent buprenorphine use (using once or less than once per week). Other factors associated with non-fatal overdoses included age, education, homelessness, as well as the benzodiazepines, stimulants, and heroin use. Conclusions:Users of diverted OSD may represent a high-risk population, as they used more additional drugs and used them more frequently than other IDUs. However, illicit OSD use may be less harmful than previously assumed. After accounting for an extensive set of covariates, only infrequent illicit buprenorphine use, but not methadone use, was associated with non-fatal overdoses.

Parental sex preferences have been documented in many native populations, but much less evidence is available on immigrants' preferences for the sexes of their children. Using high-quality longitudinal register data from Norway, a country with a recent immigration history, we estimate hazards regression models of third birth risks by the sex composition of the first two children. A central question in the extant literature is whether the sex preferences of immigrant mothers match those observed in their country of origin, or if cultural adaption to local conditions is more important. Our analyses indicate that the sex preferences of immigrants generally match those previously documented for their native population, especially in the case of son preferences. The pattern of sex preferences is unmodified by the mother's exposure to the host society. In sum, our evidence generally supports theories emphasizing cultural persistence in preferences, rather than theories of adaption or immigrant selectivity.

A substantial amount of research shows that younger siblings perform worse than their older sisters and brothers in several socioeconomic outcomes, including educational achievement. Most of these studies examined stable families and excluded half-siblings. However, the increasing prevalence of multipartnered fertility implies that many children grow up in nonnuclear families. We examine whether there is evidence for birth order effects in this context, which offers an opportunity to test and potentially expand the explanatory scope of the two main theories on birth order effects. We use comprehensive Norwegian registry data to study siblings in the 1985–1998 cohorts born to mothers or fathers who parented children with at least two partners. We provide evidence for negative effects of birth order on lower secondary school grades in both cases. Children born to fathers displaying multipartnered fertility tend to have lower grades than older full siblings but perform more similarly or better compared with older half-siblings. For siblings born to mothers with the multipartnered fertility pattern, later-born siblings do worse in school compared with all older siblings. This indicates that negative birth order effects tend to operate either within or across sets of full siblings, depending on the sex of the parent displaying multipartnered fertility. We argue that these findings can be explained by a combination of resource dilution/confluence theory and sex differences in residential arrangements following union dissolutions. We also suggest an alternative interpretation: maternal resources could be more important for generating negative birth order effects.

Why do immigrants often concentrate in low-wage workplaces with high shares of minority employees? Is workplace segregation relative to natives declining among native-born descendants of immigrants—who often achieve higher acculturation and socioeconomic progress—compared to the immigrant generation? Using rich linked employer-employee administrative data from Norway, we show that, on average, 37% and 24%, respectively, of immigrants’ and their descendants’ coworkers have immigrant background compared to 9% among natives. For economic segregation, the percentile rank of coworkers’ salary is, on average, 36, 50, and 52 for immigrants, descendants, and natives, respectively. Using information on characteristics of employees, workplaces, and residential neighborhoods, a formal decomposition shows that these factors collectively explain 33-68% and 78-80% of ethnic and socioeconomic workplace segregation, respectively, for both immigrants and their descendants. Within both generations, workers’ education and labor market attainments, industry of employment, and share of immigrant neighbors contribute most to workplace segregation relative to natives. Overall, our findings reveal a sharp decline in workplace segregation across immigrant generations, where the second generation gain improved access to workplaces in the mainstream economy.

Birth order causes social inequality between siblings. In Western countries, earlier-born perform better than later-born. In non-Western countries, however, earlier-born generally perform worse than later-born. We use administrative data to compare birth order effects between the native population and Norwegian-born children of immigrants (450,864 individuals nested within 202,191 families). The outcome is based on lower secondary school points—a combined measurement of all marks at the end of compulsory education. We found negative effects of birth order on school points for Norwegian natives. This finding is in line with previous studies from Western countries using measures of educational achievement. Birth order effects amongst Norwegian-born children of immigrant parents vary according to maternal country of origin, with some displaying similar effects as natives and others displaying no birth order effects. These findings are surprising in light of the main theories on birth order, which are universalistic and do not predict group-differences. We argue that the universalistic theories need to be supplemented to account for our findings, and discuss the potential importance of cultural variation in family-related behaviours such as strategic parenting, kindergarten attendance, and peer-influence in high-achieving immigrant groups.