Growing up in the Third Wave: democratic transitions and support for redistribution

Variation in experiences of democratic transition have durable effects on political attitudes. I find exposure to distributive narratives of democracy during democratic transitions between the ages of 18 and 25 has a durable positive effect on support for redistribution by tying economic redistribution to the idea of democracy. Using survey data from 28 countries that transitioned during the Third Wave (1980-2000), I show that these effects cannot be caused by any global period effect, survey period effect, birth cohort effect, or country-specific time-invariant characteristics. They are also robust to the inclusion of past experiences of the economy and welfare state, individual controls, and a range of modeling strategies. Using a different source of variation in democratic transitions from 2001-2020, I show that transitions cause attitudes and not the other way around. I argue that many failures of democracy in Third Wave countries are caused by the nature of the transitions from which they originated: distributive transitions produced democratic collective imaginaries irreconcilable with the amount of democratic redistribution that was forthcoming.

Improved Cognitive Function in the Tromsø Study in Norway From 2001 to 2016

Objective:Physical capacity and cardiovascular risk profiles seem to be improving in the population. Cognition have been improving due to a birth cohort effect, but evidence is conflicting on whether this improvement remains in the latest decades, and what is causing the changes in our population over 60 years old. We aimed to investigate birth cohort differences in cognition.Method:The study comprised 9514 participants from the Tromsø study, an ongoing longitudinal cohort study. Participants were in the ages 60–87 years, born between 1914 and 1956. They did four cognitive tests in three waves during 2001-2016. Linear regression was applied, and adjusted for age, education, blood pressure, smoking, hypercholesterolemia, stroke, heart attack, depression, diabetes, physical activity, alcohol use, BMI and height.Results:Cognitive test scores were better in later-born birth cohorts for all age groups, and in both sexes, compared with earlier born cohorts. Increased education, physical activity, alcohol intake, decreasing smoking prevalence and increasing height was associated with one third of this improvement across birth cohorts in women and one half of the improvement in men.Conclusion:Cognitive results were better in more recent born birth cohorts compared with earlier born, assessed at the same age. The improvement was present in all cognitive domains, suggesting an overall improvement in cognitive performance. The 80-year-olds assessed in 2015-16 performed like 60-year-olds assessed in 2001. The improved scores were associated with increased education level, increase in modest drinking frequency, increased physical activity and for men, smoking cessation and increased height.

Axial length of cataract eyes: a comparison of two cohorts over a span of 10 years apart

Background To assess the associations of axial length with age-related cataract within a span of 10 years in an Asian population in southern Taiwan. Methods A retrospective cohort study examined 960 adults who underwent cataract surgery at the Kaohsiung Chang Gung Memorial Hospital in year 2008 and year 2018. Axial length was assessed with the ultrasound biometry and/or the Zeiss IOLMaster. Eyes with prior blunt eye trauma or had underwent vitrectomy operations were excluded. The significance of the changes in axial length between the two cohorts was determined after performing age-matched analyses. Due to utilization of ultrasound biometry and/or Zeiss IOLMaster, axial length corrections with our mean difference in measurement results, which were similar to previous studies on comparison between the two measurement tools, were carried out. Results Axial length showed an age-related elongation in 10-year cross-sectional data, from a mean of 23.65 ± 1.80 mm in year 2008 to a mean of 24.30 ± 1.90 in year 2018 (p = 0.003). Patients with high myopia (axial length > 26 mm) increased significantly over the 10-year period from 8.1 to 16 % (p < 0.001). A birth cohort effect on axial length was evident as the axial lengths of year 2008 cohort were shorter than the 2018 cohort when they were in the same operation age group. In particular, persons born after the 1960s demonstrated a predominant increase in axial length in both cohorts. Conclusions Our study confirms a trend in increase of axial myopia, especially high myopias, over the 10-year period. A novel finding of this study was discovering a birth cohort effect on axial length, especially in persons born after the 1960s in southern Taiwan.

Does psychiatric molecular genetics need to account for the birth cohort effect?

Major psychiatric disorders including alcohol use disorder are considered multigenic and the smallness of effects of individual genes may be attributed to either complex biological mechanisms or geneenvironment interactions. The latter explanation is highlighted by the relatively fast changes in secular trends and in cohort effects on alcohol use disorder. Interactions of candidate gene variants with birth cohort have been found in the Estonian Children Personality Behaviour and Health Study, a longitudinal investigation from 1998 with a sample highly representative of birth cohorts within a region. Such interactions regarding initiation of alcohol use or alcohol use disorder have been revealed for e.g., 5-HTTLPR, VMAT1, OXR and NRG1, and suggest that rapid alterations in the socioeconomic environment promote changes in the genetic vulnerability to environmental risks factors such as alcohol.

Age, Period, and Cohort Effects on Suicide Mortality in South Korea, 1992–2015

Although the effects of age, period, and cohort (APC) on suicide are important, previous work in this area may have been invalid because of an identification problem. We analyzed these effects under three different scenarios to identify vulnerable groups and thus overcame the identification problem. We extracted the annual numbers of suicides from the National Death Register of Korea (1992–2015) and estimated the APC effects. The annual average suicide rates in 1992–2015 were 31.5 and 14.7 per 100,000 males and females, respectively. The APC effects on suicide were similar in both sexes. The age effect was clearly higher in older subjects, in contrast to the minimal changes apparent during earlier adulthood. The birth cohort effect showed an inverted U shape; a higher cohort effect was evident in females born in the early 1980s when period drift was larger than 3.7%/year. Period effect increased sharply during the early 1990s and 2000s. We found that elderly and young females may be at a particularly high risk of suicide in Korea.

Influence of birth cohort on age of onset cluster analysis in bipolar I disorder

Purpose:Two common approaches to identify subgroups of patients with bipolar disorder are clustering methodology (mixture analysis) based on the age of onset, and a birth cohort analysis. This study investigates if a birth cohort effect will influence the results of clustering on the age of onset, using a large, international database.Methods:The database includes 4037 patients with a diagnosis of bipolar I disorder, previously collected at 36 collection sites in 23 countries. Generalized estimating equations (GEE) were used to adjust the data for country median age, and in some models, birth cohort. Model-based clustering (mixture analysis) was then performed on the age of onset data using the residuals. Clinical variables in subgroups were compared.Results:There was a strong birth cohort effect. Without adjusting for the birth cohort, three subgroups were found by clustering. After adjusting for the birth cohort or when considering only those born after 1959, two subgroups were found. With results of either two or three subgroups, the youngest subgroup was more likely to have a family history of mood disorders and a first episode with depressed polarity. However, without adjusting for birth cohort (three subgroups), family history and polarity of the first episode could not be distinguished between the middle and oldest subgroups.Conclusion:These results using international data confirm prior findings using single country data, that there are subgroups of bipolar I disorder based on the age of onset, and that there is a birth cohort effect. Including the birth cohort adjustment altered the number and characteristics of subgroups detected when clustering by age of onset. Further investigation is needed to determine if combining both approaches will identify subgroups that are more useful for research.