scholarly journals Global estimation and scenario-based projections of sex ratio at birth and missing female births using a Bayesian hierarchical time series mixture model

2021 ◽  
Vol 15 (3) ◽  
Author(s):  
Fengqing Chao ◽  
Patrick Gerland ◽  
Alex R. Cook ◽  
Leontine Alkema
Keyword(s):  
Time Series ◽  
Sex Ratio ◽  
Mixture Model ◽  
Sex Ratio At Birth ◽  
Bayesian Hierarchical ◽  
Global Estimation

scholarly journals Sex ratio at birth in Vietnam among six subnational regions during 1990–2050, estimation and probabilistic projection using a Bayesian hierarchical time series model

2021 ◽  
Author(s):  
Fengqing Chao ◽  
Christophe Z. Guilmoto ◽  
Hernando Ombao
Keyword(s):  
Time Series ◽  
Sex Ratio ◽  
Local Maximum ◽  
Credible Interval ◽  
River Delta ◽  
Red River ◽  
Sex Ratio At Birth ◽  
Red River Delta ◽  
Mountain Areas ◽  
Bayesian Hierarchical

The sex ratio at birth (SRB, i.e., the ratio of male to female births) in Vietnam has been imbalanced since the 2000s. Previous studies have revealed a rapid increase in the SRB over the past 15 years and the presence of important variations across regions. More recent studies suggested that the nation’s SRB may have plateaued during the 2010s. Given the lack of exhaustive birth registration data in Vietnam, it is necessary to estimate and project levels and trends in the regional SRBs in Vietnam based on a reproducible statistical approach. We compiled an extensive database on regional Vietnam SRBs based on all publicly available surveys and censuses and used a Bayesian hierarchical time series mixture model to estimate and project SRB in Vietnam by region from 1980 to 2050. The Bayesian model incorporates the uncertainties from the observations and year-by-year natural fluctuation. It includes a binary parameter to detect the existence of sex ratio transitions among Vietnamese regions. Furthermore, we model the SRB imbalance using a trapezoid function to capture the increase, stagnation, and decrease of the sex ratio transition by Vietnamese regions. The model results show that four out of six Vietnamese regions, namely, Northern Midlands and Mountain Areas, Northern Central and Central Coastal Areas, Red River Delta, and South East, have existing sex imbalances at birth. The rise in SRB in the Red River Delta was the fastest, as it took only 12 years and was more pronounced, with the SRB reaching the local maximum of 1.146 with a 95% credible interval (1.129, 1.163) in 2013. The model projections suggest that the current decade will record a sustained decline in sex imbalances at birth, and the SRB should be back to the national SRB baseline level of 1.06 in all regions by the mid-2030s.

scholarly journals Sex ratio at birth in Vietnam among six subnational regions during 1980–2050, estimation and probabilistic projection using a Bayesian hierarchical time series model with 2.9 million birth records

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0253721
Author(s):  
Fengqing Chao ◽  
Christophe Z. Guilmoto ◽  
Hernando Ombao
Keyword(s):  
Time Series ◽  
Sex Ratio ◽  
Local Maximum ◽  
Credible Interval ◽  
River Delta ◽  
Red River ◽  
Sex Ratio At Birth ◽  
Red River Delta ◽  
Mountain Areas ◽  
Bayesian Hierarchical

The sex ratio at birth (SRB, i.e., the ratio of male to female births) in Vietnam has been imbalanced since the 2000s. Previous studies have revealed a rapid increase in the SRB over the past 15 years and the presence of important variations across regions. More recent studies suggested that the nation’s SRB may have plateaued during the 2010s. Given the lack of exhaustive birth registration data in Vietnam, it is necessary to estimate and project levels and trends in the regional SRBs in Vietnam based on a reproducible statistical approach. We compiled an extensive database on regional Vietnam SRBs based on all publicly available surveys and censuses and used a Bayesian hierarchical time series mixture model to estimate and project SRB in Vietnam by region from 1980 to 2050. The Bayesian model incorporates the uncertainties from the observations and year-by-year natural fluctuation. It includes a binary parameter to detect the existence of sex ratio transitions among Vietnamese regions. Furthermore, we model the SRB imbalance using a trapezoid function to capture the increase, stagnation, and decrease of the sex ratio transition by Vietnamese regions. The model results show that four out of six Vietnamese regions, namely, Northern Midlands and Mountain Areas, Northern Central and Central Coastal Areas, Red River Delta, and South East, have existing sex imbalances at birth. The rise in SRB in the Red River Delta was the fastest, as it took only 12 years and was more pronounced, with the SRB reaching the local maximum of 1.146 with a 95% credible interval (1.129, 1.163) in 2013. The model projections suggest that the current decade will record a sustained decline in sex imbalances at birth, and the SRB should be back to the national SRB baseline level of 1.06 in all regions by the mid-2030s.

scholarly journals Projecting sex imbalances at birth at global, regional, and national levels from 2018 to 2100: scenario-based Bayesian probabilistic projections of the sex ratio at birth and missing female births

2021 ◽  
Author(s):  
Fengqing Chao ◽  
Patrick Gerland ◽  
Alex R. Cook ◽  
Christophe Z. Guilmoto ◽  
Leontine Alkema
Keyword(s):  
At Risk ◽  
Sex Ratio ◽  
Sex Discrimination ◽  
Reference Scenario ◽  
Sex Ratio At Birth ◽  
Uncertainty Interval ◽  
Bayesian Hierarchical ◽  
Sub Saharan ◽  
To Come

Introduction: Skewed levels of the sex ratio at birth (SRB) due to sex-selective abortions have been observed in several countries since the 1970s. They will lead to long-term sex imbalances in more than a third of the world’s population with yet unknown social and economic impacts on affected countries. Understanding the potential evolution of sex imbalances at birth is therefore essential for anticipating and planning for changing sex structures across the world. Methods: We produced probabilistic SRB projections from 2018 to 2100 based on different scenarios of sex ratio transition and assessed their implications in terms of missing female births at global, regional, and national levels. Based on a comprehensive SRB database, we project the skewed SRB and missing female births with a Bayesian hierarchical time series mixture model. The SRB projections under reference scenario S1 assumed SRB transitions only for countries with strong statistical evidence of SRB inflation, and the more extreme scenario S2 assumed a sex ratio transition for countries at risk of SRB inflation but with no or limited evidence of ongoing inflation.Results: Under scenario S1, we projected 8.1 (95% uncertainty interval [2.3; 19.6]) million additional missing female births to occur by 2100. Countries affected will be those already affected in the past by imbalanced SRB, such as China and India. If all countries at risk of SRB inflation experience a sex ratio transition as in scenario S2, the projected missing female births increase to 24.8 [13.1; 44.1] million with a sizeable contribution of sub-Saharan Africa.Conclusion: The scenario-based projections provide important illustrations of the potential burden of future prenatal sex discrimination and the need to monitor SRBs in countries with son preference. Policy planning will be needed in the years to come to minimize future prenatal sex discrimination and its impact on social structures.

scholarly journals Levels and trends in sex ratio at birth in provinces of Pakistan from 1980 to 2020 with scenario-based missing female birth projections to 2050: a Bayesian modeling approach

2021 ◽  
Author(s):  
Fengqing Chao ◽  
Muhammad Asif Wazir ◽  
Hernando Ombao
Keyword(s):  
Sex Ratio ◽  
Sex Discrimination ◽  
Credible Interval ◽  
Sex Ratio At Birth ◽  
Bayesian Hierarchical ◽  
Female Birth ◽  
Child Mortality Rate ◽  
Birth Records ◽  
Male To Female ◽  
Postnatal Stage

BACKGROUND: Pakistan has a strong preference for boys over girls; previous evidence on sex preference is primarily reported at the postnatal stage in which the child mortality rate is higher for females than males. Prenatal sex discrimination in Pakistan, reflected in the inflated sex ratio at birth (SRB; ratio of male to female births) has been barely mentioned before this study.OBJECTIVE: We estimate the SRB and missing female births in Pakistan provinces from 1980 to 2020 and identify provinces with imbalanced SRB. We provide scenario-based projections of missing female births in provinces without the existing SRB inflation.METHODS: An extensive SRB database of 832,091 birth records was compiled from all available surveys and censuses. To synthesize different data sources and provide annual estimates and their associated uncertainties of SRBs across provinces, we adopted a Bayesian hierarchical time series model.RESULTS: As per our model, Balochistan has had SRB imbalance since 1980. The maximum SRB was estimated as 1.121 (95% credible interval [1.066; 1.142]) in 1997. Assuming different start year of SRB inflation process in provinces without existing imbalance, the largest female birth deficit is projected to be 76.2 thousand in Punjab in 2033 when the SRB inflation starts in 2021.CONTRIBUTION: This is the first study on estimating the SRB from 1980 to 2020 and providing scenario-based projections of missing female births up to 2050 by Pakistan province. We identified the Balochistan province with imbalanced SRB and demonstrated important disparities in the occurrence and quantity of female birth deficits before 2050.

scholarly journals Projecting sex imbalances at birth at global, regional and national levels from 2021 to 2100: scenario-based Bayesian probabilistic projections of the sex ratio at birth and missing female births based on 3.26 billion birth records

2021 ◽  
Vol 6 (8) ◽  
pp. e005516
Author(s):  
Fengqing Chao ◽  
Patrick Gerland ◽  
Alex Richard Cook ◽  
Christophe Z Guilmoto ◽  
Leontine Alkema
Keyword(s):  
At Risk ◽  
Sex Ratio ◽  
Sex Discrimination ◽  
Sub Saharan Africa ◽  
Reference Scenario ◽  
Sex Ratio At Birth ◽  
Uncertainty Interval ◽  
Bayesian Hierarchical ◽  
Sub Saharan ◽  
Birth Records

IntroductionSkewed levels of the sex ratio at birth (SRB) due to sex-selective abortions have been observed in several countries since the 1970s. They will lead to long-term sex imbalances in more than one-third of the world’s population with yet unknown social and economic impacts on affected countries. Understanding the potential evolution of sex imbalances at birth is therefore essential for anticipating and planning for changing sex structures across the world.MethodsWe produced probabilistic SRB projections from 2021 to 2100 based on different scenarios of sex ratio transition and assessed their implications in terms of missing female births at global, regional and national levels. Based on a comprehensive SRB database with 3.26 billion birth records, we project the skewed SRB and missing female births with a Bayesian hierarchical time series mixture model. The SRB projections under reference scenario S1 assumed SRB transitions only for countries with strong statistical evidence of SRB inflation, and the more extreme scenario S2 assumed a sex ratio transition for countries at risk of SRB inflation but with no or limited evidence of ongoing inflation.ResultsUnder scenario S1, we projected 5.7 (95% uncertainty interval (1.2; 15.3)) million additional missing female births to occur by 2100. Countries affected will be those already affected in the past by imbalanced SRB, such as China and India. If all countries at risk of SRB inflation experience a sex ratio transition as in scenario S2, the projected missing female births increase to 22.1 (12.2; 39.8) million with a sizeable contribution of sub-Saharan Africa.ConclusionThe scenario-based projections provide important illustrations of the potential burden of future prenatal sex discrimination and the need to monitor SRBs in countries with son preference. Policy planning will be needed in the years to come to minimise future prenatal sex discrimination and its impact on social structures.

scholarly journals Combatting the imbalance of sex ratio at birth: medium-term impact of India’s National Programme of Beti Bachao Beti Padhao in the Haryana State of India

2021 ◽  
Author(s):  
Rakesh Gupta ◽  
Girdhari Lal Singhal ◽  
Aarti Goyal ◽  
Gurjinder Kaur ◽  
Neha Purohit ◽  
...  
Keyword(s):  
Time Series ◽  
Sex Ratio ◽  
Confidence Interval ◽  
Social Protection ◽  
Child Survival ◽  
Sex Ratio At Birth ◽  
Medium Term ◽  
Time Series Regression ◽  
Registration System ◽  
The Government

Abstract The Government of India initiated the Beti Bachao Beti Padhao (B3P) programme in 2015 as a flagship initiative to reduce gender imbalance in sex ratio at birth (SRB) and to ensure social protection of girls. The present study was conducted to evaluate the medium-term impact of B3P implementation in Haryana state, from 2015 to 2019, on SRB. Monthly data on SRB were collected for the entire state of Haryana through a civil registration system. Segmented time series regression analysis was used to estimate the variations in SRB after the B3P programme with the help of Winter’s additive interrupted time series model. The SRB in Haryana increased from 876 girls per 1000 boys in 2015 to 923 in 2019. The results of the model demonstrated that before the inception of intervention (pre-slope), there was a significant monthly change in SRB of 0.217 (95% confidence interval: 0.144–0.290). Following the B3P programme, SRB was found to increase by 0.835 per month, which implied that an increase of 0.618 (confidence interval: 0.338, 0.898) every month in SRB can be attributed to the B3P programme. This indicated that SRB for the state of Haryana increased at the rate of 7.42 units per year as a result of the B3P programme. B3P has led to a significant improvement in SRB in Haryana state. The continuity of efforts in the same direction with a sustained focus on behaviour change will further help achieve the goal of gender parity in births and child survival.

scholarly journals Recent sex ratio at birth in China

2021 ◽  
Vol 6 (5) ◽  
pp. e005438
Author(s):  
Quanbao Jiang ◽  
Cuiling Zhang
Keyword(s):  
Sex Ratio ◽  
Normal Level ◽  
Decomposition Methods ◽  
Sex Ratio At Birth ◽  
Negative Effects ◽  
Female Fetus ◽  
The Past ◽  
Multiple Data ◽  
Child Policy ◽  
Second Births

BackgroundChina’s sex ratio at birth (SRB) has declined in the past decade but still exceeds the normal level. This study seeks to depict the SRB trend in the past two decades.MethodsWe depicted the SRB trend, including SRB by birth order, children composition, residence and hukou type, education, race and province using latest data available from multiple data sources and standardisation and decomposition methods.ResultsThe SRB remained around 120 in the first decade from 2000 to 2010, and recently declined and approached the normal level during 2010–2020. The SRB for second births and first births converged to the normal level, whereas the SRB for third and above births exceeded the normal level. The rising proportion of second births increased, whereas the decreasing proportion of first births reduced the overall SRB. Parents with only daughters are more likely to abort a female fetus in pursuit of a son, while parents with only sons are more likely to abort a male fetus in pursuit of a daughter. It also shows difference in SRB by residence, hukou type, educational attainment and race. Urban SRB was lower than rural SRB, by the residence and hukou type, but higher than rural SRB after being standardised. Provinces still exhibit differences by original categorised policy even after the implementation of the universal two-child policy.ConclusionsChina’s SRB has declined substantially during the past two decades, but the negative effects need to be tackled.

Exact Likelihood Evaluation in a Markov Mixture Model for Time Series of Seizure Counts

Biometrics ◽  
1992 ◽  
Vol 48 (1) ◽  
pp. 317 ◽  
Author(s):  
Nhu D. Le ◽  
Brian G. Leroux ◽  
Martin L. Puterman ◽  
Paul S. Albert
Keyword(s):  
Time Series ◽  
Mixture Model

Akodon molinae (Rodentia Cricetidae), a new laboratory animal: breeding, management and reproductive performance

1980 ◽  
Vol 14 (2) ◽  
pp. 129-131 ◽  
Author(s):  
Maria Susana Merani ◽  
Marta Susana Lizarralde
Keyword(s):  
Sex Ratio ◽  
Reproductive Performance ◽  
Sexual Maturity ◽  
Laboratory Animal ◽  
Post Partum ◽  
Animal Breeding ◽  
Haemorrhagic Fever ◽  
Sex Ratio At Birth ◽  
Breeding Management ◽  
Laboratory Colony

Akodon molinae, a vole mouse widely distributed in central Argentina, shows remarkable chromosome polymorphisms. It is one of the natural reservoirs of the actiologic agent of haemorrhagic fever, and a laboratory colony could be of great help in investigating this disease. Pregnancy lasted 23 (range 21-25) days. Litters of 4-5 young were born to monogamous breeding pairs about every 30 days, with weaning at 26 days post partum. The sex ratio at birth was 505 males to 500 females: at weaning it was 460 to 440. Sexual maturity was attained at about 16 weeks of age in males and 12-20 weeks in females. Akodon molinae is easy to handle, but fighting and killing or neglect of young are problems.

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