The range of estimates of excess deaths under Pol Pot's rule of Cambodia (1975-79) is too wide to be useful: they range from under 1 to over 3 million, with the more plausible estimates still varying from 1 to 2 million. By stochastically reconstructing population dynamics in Cambodia from extant historical and demographic data, we produced interpretable distributions of the death toll and other demographic indicators. The resulting 95 per cent simulation interval (1.2-2.8 million excess deaths) demonstrates substantial uncertainty over the exact scale of mortality, yet it still excludes nearly half of the previous death-toll estimates. The 1.5-2.25 million interval contains 69 per cent of the simulations for the actual number of excess deaths, more than the wider (1-2 million) range of previous plausible estimates. The median value of 1.9 million excess deaths represents 21 per cent of the population at risk. Supplementary material for this article is available at: http://dx.doi.org/10.1080/00324728.2015.1045546.

Timely, high-quality mortality data have allowed for assessments of the impact of the novel coronavirus disease 2019 (COVID-19) on life expectancies in upper-middle- and high-income countries. Extant data, though imperfect, suggest that the bulk of the pandemic-induced mortality might have occurred elsewhere. This article reports on changes in life expectancies around the world as far as they can be estimated from the evidence available at the end of 2021. The global life expectancy appears to have declined by 0.92 years between 2019 and 2020 and by another 0.72 years between 2020 and 2021, but the decline seems to have ended during the last quarter of 2021. Uncertainty about its exact size aside, this represents the first decline in global life expectancy since 1950, the first year for which a global estimate is available from the United Nations. Annual declines in life expectancy (from a 12-month period to the next) appear to have exceeded two years at some point before the end of 2021 in at least 50 countries. Since 1950, annual declines of that magnitude had only been observed on rare occasions, such as Cambodia in the 1970s, Rwanda in the 1990s, and possibly some sub-Saharan African nations at the peak of the acquired immunodeficiency syndrome (AIDS) pandemic.

We analyze the effects of household structure on education in Cambodia. Consistent evidence documents that residence with both biological parents benefits children's education in Western countries. Elsewhere, the issue is gaining more attention with the growing number of "left-behind children" due to adult migration and, possibly, changes in family behavior, but the extant record is both thinner and more contrasted. Controlling for the presence of grandparents and some household characteristics, we find children residing with both biological parents are more likely to be enrolled in school, in the appropriate grade for their age, and literate than those living with only one parent. The effect sizes appear comparable to those in most Western countries, but the effects shrink or even disappear when grandparents are present. The results for children not residing with either parent are mixed, suggesting negative effects for some children might be blurred by positive selection for some others.

Objectives

Following well-established practices in demography, this article discusses several measures based on the number of COVID-19 deaths to facilitate comparisons over time and across populations.

Settings

National populations in 186 United Nations countries and territories and populations in first-level subnational administrative entities in Brazil, China, Italy, Mexico, Peru, Spain and the USA.

Participants

None (death statistics only).

Primary and secondary outcome measures

An unstandardised occurrence/exposure rate comparable to the Crude Death Rate; an indirectly age-and-sex standardised rate that can be derived even when the breakdown of COVID-19 deaths by age and sex required for direct standardisation is unavailable; the reduction in life expectancy at birth corresponding to the 2020 number of COVID-19 deaths.

Results

To date, the highest unstandardised rate has been in New York, at its peak exceeding the state 2017 crude death rate. Populations compare differently after standardisation: while parts of Italy, Spain and the USA have the highest unstandardised rates, parts of Mexico and Peru have the highest standardised rates. For several populations with the necessary data by age and sex for direct standardisation, we show that direct and indirect standardisation yield similar results. US life expectancy is estimated to have declined this year by more than a year (-1.26 years), far more than during the worst year of the HIV epidemic, or the worst 3 years of the opioid crisis, and to reach its lowest level since 2008. Substantially larger reductions, exceeding 2 years, are estimated for Panama, Peru, and parts of Italy, Spain, the USA and especially, Mexico.

Conclusions

With lesser demand on data than direct standardisation, indirect standardisation is a valid alternative to adjust international comparisons for differences in population distribution by sex and age-groups. A number of populations have experienced reductions in 2020 life expectancies that are substantial by recent historical standards.

Non-marital births and divorce remain rare in Cambodia. Due to dramatic levels of adult mortality reached during the late 1970s, growing up with a single parent is not. Using nationally representative, cross-sectional data, we estimate that about 12% of children under age 18 co-reside with only one of their biological parents. Using longitudinal data representative of the Mekong River Valley, we find this proportion to be declining. Nearly half of these children live in nuclear families (single parent with or without a step-parent), even though they live in multigenerational families more frequently than children who live with both their parents, especially, when young and not living with their mother. Last, we consider differences in socioeconomic conditions and child educational outcomes by number of co-residing parents.

Adverse childhood events (ACE) may have lasting consequences throughout the life course. We focus on one particular type of ACE, parental loss in Cambodia-a country that lost nearly 25% of its population during the 1975-79 Khmer-Rouge regime-and on mental health disorders, one of the potential mechanisms through which ACE may have long-term consequences. Self-reports of symptoms that map on to the Diagnostic and Statistical Manual of Mental Health Disorders (DSM) criteria for anxiety, depression, and post-traumatic stress disorder (PTSD) were collected from 4,405 adults aged 20 and over. We first assess exposure to traumatic events and the prevalence of anxiety, depression, and PTSD using the DSM and alternative criteria. Based on the DSM criteria and previously validated Likert-scale thresholds, we find a high prevalence of anxiety (56.0%), depression (42.8%), and PTSD (2.3%), and even higher levels even among KRR survivors. We then use logit models to analyze the effect of parental loss before age 20 on the likelihood of having experienced traumatic events and experiencing mental health disorders. We find the loss of one parent increases the likelihood of full-PTSD symptoms, but the loss of both parents does not. These findings may result from positive selection into better-off households for orphans whose parents have both died but may also reflect the grief-related difficulties faced by the surviving parent of paternal or maternal orphans. While alternative thresholds for PTSD produced higher prevalence estimates, these measures did not perform better for assessing the effect of parental loss on mental health.