Long-term population projections: Scenarios of low or rebounding fertility.

The size of the human population is projected to peak in the 21st century. But quantitative projections past 2100 are rare, and none quantify the possibility of a rebound from low fertility to replacement-level fertility. Moreover, the most recent long-term deterministic projections were published a decade ago; since then there has been further global fertility decline. Here we provide updated long-term cohort-component population projections and extend the set of scenarios in the literature to include scenarios in which future fertility (a) stays below replacement or (b) recovers and increases. We also characterize old-age dependency ratios. We show that any stable, long-run size of the world population would persistently depend on when an increase towards replacement fertility begins. Without such an increase, the 400-year span when more than 2 billion people were alive would be a brief spike in history. Indeed, four-fifths of all births-past, present, and future-would have already happened.

Foundations of utilitarianism under risk and variable population.

Utilitarianism is the most prominent social welfare function in economics. We present three new axiomatic characterizations of utilitarian (that is, additively-separable) social welfare functions in a setting where there is risk over both population size and individuals' welfares. We first show that, given uncontroversial basic axioms, Blackorby et al.'s (1998) Expected Critical-Level Generalized Utilitarianism is equivalent to a new axiom holding that it is better to allocate higher utility-conditional-on-existence to possible people who have a higher probability of existence. The other two characterizations extend and clarify classic axiomatizations of utilitarianism from settings with either social risk or variable-population, considered alone.

Understanding the rise in traditional contraceptive methods use in Uttar Pradesh, India.

BACKGROUND: The sustainable development goals (SDG) aim at satisfying three-fourths of family planning needs through modern contraceptive methods by 2030. However, the traditional methods (TM) of family planning use are on the rise, along with modern contraception in Uttar Pradesh (UP), the most populous Indian state. This study attempts to explore the dynamics of rising TM use in the state. METHODS: We used a state representative cross-sectional survey conducted among 12,200 Currently Married Women (CMW) aged 15-49 years during December 2020-February 2021 in UP. Using a multistage sampling technique, 508 primary sampling units (PSU) were selected. These PSU were ASHA areas in rural settings and Census Enumeration Blocks in urban settings. About 27 households from each PSU were randomly selected. All the eligible women within the selected households were interviewed. The survey also included the nearest public health facilities to understand the availability of family planning methods. Univariate and bivariate analyses were conducted. Appropriate sampling weights were applied. RESULTS: Overall, 33.9% of CMW were using any modern methods and 23.7% any TM (Rhythm and withdrawal) at the time of survey. The results show that while the modern method use has increased by 2.2 percentage points, the TM use increased by 9.9 percentage points compared to NFHS-4 (2015-16). The use of TM was almost same across women of different socio-demographic characteristics. Of 2921 current TM users, 80.7% started with TM and 78.3% expressed to continue with the same in future. No side effects (56.9%), easy to use (41.7%) and no cost incurred (38.0%) were the main reasons for the continuation of TM. TM use increased despite a significant increase (66.1 to 81.3%) in the availability of modern reversible methods and consistent availability of limiting methods (84.0%) in the nearest public health facilities. CONCLUSION: Initial contraceptive method was found to have significant implications for current contraceptive method choice and future preferences. Program should reach young and zero-parity women with modern method choices by leveraging front-line workers in rural UP. Community and facility platforms can also be engaged in providing modern method choices to women of other parities to increase modern contraceptive use further to achieve the SDG goals.

In Uttar Pradesh, the use of traditional methods of contraception is on the rise, observed similarly in many other Indian states in recent times. The emphasis on modern contraceptive methods and the rise and high prevalence of traditional method use in the state call for a systematic assessment to understand the dynamics such as patterns, prevalence and reasons for traditional method use for better family planning programming. Using a state representative cross-sectional survey data from Uttar Pradesh, we attempted to understand the dynamics of increasing traditional methods use. We found no significant variations in use of traditional methods by their socio-demographic characteristics. Not only that, most current traditional method users reported that their first method was a traditional method and an overwhelming proportion of women (4/5 traditional methods users) expressed to continue with the same method in future. Also the findings reveal that more than half of the traditional method users used the method consistently over the three-years calendar period. Among those who had unmet need at the time of survey, a considerable proportion of them intend to use traditional methods in future. This emphasized the importance of initial contraceptive method choice on current contraceptive use and future preference. Traditional methods use increased in the state despite a significant increase (66.1 to 81.3% during 2018 to 2021) in availability of modern reversible methods and consistent availability of limiting method (84.0%) in public health facilities.

Near-universal marriage, early childbearing, and low fertility: India's alternative fertility transition.

OBJECTIVE: To compare fertility in India to both low-to-middle-income and high-income countries (LMICs and HICs) and describe the patterns that have accompanied India's transition to low fertility. METHODS: We use data from the Demographic and Health Surveys (DHS), the United Nations (UN), and the Organisation for Economic Co-operation and Development (OECD) to observe factors associated with fertility decline in 36 Indian states and 76 countries. RESULTS: Although fertility in India has declined to levels similar to HICs, women's entry into marriage and initiation of childbearing are more in line with patterns found in LMICs. The vast majority of women in India (97%) are married by age 30, and their average age at first birth is only 21.3 years old. In spite of these patterns, average fertility has declined in India as a result of earlier termination of childbearing. Among more recent cohorts, fewer women progressed to higher-order births and about half of women obtained a sterilization by age 35. CONCLUSIONS: India has reached low fertility by mechanisms outside the traditional indicators of fertility decline. In contrast to countries that have achieved low fertility through delayed age at first birth, women in India have continued to enter unions and bear children early, lowered their age at last birth, and increasingly ended their fertility via sterilization following the birth of two children. CONTRIBUTION: Evidence from India reveals an alternative pathway to low fertility, highlighting the limitations of traditional socioeconomic indicators for explaining fertility decline.

Research Note: Intergenerational Transmission Is Not Sufficient for Positive Long-Term Population Growth.

All leading long-term global population projections agree on continuing fertility decline, resulting in a rate of population size growth that will continue to decline toward zero and would eventually turn negative. However, scholarly and popular arguments have suggested that because fertility transmits intergenerationally (i.e., higher fertility parents tend to have higher fertility children) and is heterogeneous within a population, long-term population growth must eventually be positive, as high-fertility groups come to dominate the population. In this research note, we show that intergenerational transmission of fertility is not sufficient for positive long-term population growth, for empirical and theoretical reasons. First, because transmission is imperfect, the combination of transmission rates and fertility rates may be quantitatively insufficient for long-term population growth: higher fertility parents may nevertheless produce too few children who retain higher fertility preferences. Second, today even higher fertility subpopulations show declining fertility rates, which may eventually fall below replacement (and in some populations already are). Therefore, although different models of fertility transmission across generations reach different conclusions, depopulation is likely under any model if, in the future, even higher fertility subpopulations prefer and achieve below-replacement fertility. These results highlight the plausibility of long-term global depopulation and the importance of understanding the possible consequences of depopulation.

Mothers' Social Status and Children's Health: Evidence From Joint Households in Rural India.

The premise that a woman's social status has intergenerational effects on her children's health has featured prominently in population science research and in development policy. This study focuses on an important case in which social hierarchy has such an effect. In joint patrilocal households in rural India, women married to the younger brother are assigned lower social rank than women married to the older brother in the same household. Almost 8% of rural Indian children under 5 years old-more than 6 million children-live in such households. We show that children of lower-ranking mothers are less likely to survive and have worse health outcomes, reflected in higher neonatal mortality and shorter height, compared with children of higher-ranking mothers in the same household. That the variation in mothers' social status that we study is not subject to reporting bias is an advantage relative to studies using self-reported measures. We present evidence that one mechanism for this effect is maternal nutrition: although they are not shorter, lower-ranking mothers weigh less than higher-ranking mothers. These results suggest that programs that merely make transfers to households without attention to intrahousehold distribution may not improve child outcomes.

Endogenous inclusion in the Demographic and Health Survey anthropometric sample: Implications for studying height within households.

Development economists study both anthropometry and intra-household allocation. In these literatures, the Demographic and Household Surveys (DHS) are essential. The DHS censors its anthropometric sample by age: only children under five are measured. We document several econometric consequences, especially for estimating birth-order effects. Child birth order and mothers' fertility are highly correlated in the age-censored anthropometric subsample. Moreover, family structures and age patterns that permit within-family comparisons of siblings' anthropometry are unrepresentative. So strategies that could separate birth order and fertility in other data cannot here. We show that stratification by mother's fertility is important. We illustrate this by comparing India and sub-Saharan Africa (SSA). Children in India born to higher-fertility mothers are shorter, on average, than children of lower-fertility mothers. Yet, later-born children in India are taller, adjusted for age, than earlier-born children of the same sibsize. In SSA, neither of these associations is large.

Inversions in US Presidential Elections: 1836-2016.

Inversions-in which the popular vote winner loses the election-have occurred in four US presidential races. We show that rather than being statistical flukes, inversions have been ex ante likely since the early 1800s. In elections yielding a popular vote margin within 1 point (one-eighth of presidential elections), about 40 percent will be inversions in expectation. We show this conditional probability is remarkably stable across historical periods-despite differences in which groups voted, which states existed, and which parties participated. Our findings imply that the United States has experienced so few inversions merely because there have been so few elections (and fewer close elections).

Repugnant Conclusions.

The population ethics literature has long focused on attempts to avoid the repugnant conclusion. We show that a large set of social orderings that are conventionally understood to escape the repugnant conclusion do not in fact avoid it in all instances. As we demonstrate, prior results depend on formal definitions of the repugnant conclusion that exclude some repugnant cases, for reasons inessential to any "repugnance" (or other meaningful normative properties) of the repugnant conclusion. In particular, the literature traditionally formalizes the repugnant conclusion to exclude cases that include an unaffected sub-population. We relax this normatively irrelevant exclusion, and others. Using several more inclusive formalizations of the repugnant conclusion, we then prove that any plausible social ordering implies some instance of the repugnant conclusion. This understanding - that it is impossible to avoid all instances of the repugnant conclusion - is broader than the traditional understanding in the literature that the repugnant conclusion can only be escaped at unappealing theoretical costs. Therefore, the repugnant conclusion provides no methodological guidance for theory or policy-making, because it does not discriminate among candidate social orderings. So escaping the repugnant conclusion should not be a core goal of the population ethics literature.

Population ethics and the prospects for fertility policy as climate mitigation policy.

What are the prospects for using population policy as tool to reduce carbon emissions? In this paper, we review evidence from population science, in order to inform debates in population ethics that, so far, have largely taken place within the academic philosophy literature. In particular, we ask whether fertility policy is likely to have a large effect on carbon emissions, and therefore on temperature change. Our answer is no. Prospects for a policy of fertility-reduction-as-climate-mitigation are limited by population momentum, a demographic factor that limits possible variation in the size of the population, even if fertility rates change very quickly. In particular, a hypothetical policy that instantaneously changed fertility and mortality rates to replacement levels would nevertheless result in a population of over 9 billion people in 2060. We use a leading climate-economy model to project the consequence of such a hypothetical policy for climate change. As a standalone mitigation policy, such a hypothetical change in the size of the future population - much too large to be implementable by any foreseeable government program - would reduce peak temperature change only to 6.4°C, relative to 7.1°C under the most likely population path. Therefore, fertility reduction is unlikely to be an adequate core approach to climate mitigation.

Additively-separable and rank-discounted variable-population social welfare functions: A characterization.

Economic policy evaluations require social welfare functions for variable-size populations. Two important candidates are critical-level generalized utilitarianism (CLGU) and rank-discounted critical-level generalized utilitarianism, which was recently characterized by Asheim and Zuber (2014) (AZ). AZ introduce a novel axiom, existence of egalitarian equivalence (EEE). First, we show that, under some uncontroversial criteria for a plausible social welfare relation, EEE suffices to rule out the Repugnant Conclusion of population ethics (without AZ's other novel axioms). Second, we provide a new characterization of CLGU: AZ's set of axioms is equivalent to CLGU when EEE is replaced by the axiom same-number independence.

NEONATAL DEATH IN INDIA: BIRTH ORDER IN A CONTEXT OF MATERNAL UNDERNUTRITION.

We document a novel fact about neonatal death, or death in the first month of life. Globally, neonatal mortality is disproportionately concentrated in India. We identify a large effect of birth order on neonatal mortality that is unique to India: later-born siblings have a steep survival advantage relative to the birth-order gradient in other developing countries. We show that India's high prevalence of maternal undernutrition and its correlation with age and childbearing can explain this pattern. We find that Indian mothers exit the underweight body mass range at an internationally comparatively high rate as they progress through childbearing careers.

Climate action with revenue recycling has benefits for poverty, inequality and well-being.

Existing estimates of optimal climate policy ignore the possibility that carbon tax revenues could be used in a progressive way; model results therefore typically imply that near-term climate action comes at some cost to the poor. Using the Nested Inequalities Climate Economy (NICE) model, we show that an equal per capita refund of carbon tax revenues implies that achieving a 2°C target can pay large and immediate dividends for improving well-being, reducing inequality and alleviating poverty. In an optimal policy calculation that weighs the benefits against the costs of mitigation, the recommended policy is characterized by aggressive near-term climate action followed by a slower climb towards full decarbonization; this pattern-which is driven by a carbon revenue Laffer curve-prevents runaway warming while also preserving tax revenues for redistribution. Accounting for these dynamics corrects a long-standing bias against strong immediate climate action in the optimal policy literature.

Those who can't sort, steal: caste, occupational mobility, and rent-seeking in rural India.

Three important features of Indian labor markets enduringly coexist: rent-seeking, occupational immobility, and caste. These facts are puzzling, given theories that predict static, equilibrium social inequality without conflict. Our model explains these facts as an equilibrium outcome. Some people switch caste-associated occupations for an easier source of rents, rather than for productivity. This undermines trust between castes and shuts down occupational mobility, which further encourages rent-seeking due to an inability of workers to sort into occupations. We motivate our contribution with novel stylized facts exploiting a unique survey question on casteism in India, which we show is associated with rent-seeking.

Utilitarian benchmarks for emissions and pledges promote equity, climate and development.

Tools are needed to benchmark carbon emissions and pledges against criteria of equity and fairness. However, standard economic approaches, which use a transparent optimization framework, ignore equity. Models that do include equity benchmarks exist, but often use opaque methodologies. Here we propose a utilitarian benchmark computed in a transparent optimization framework, which could usefully inform the equity benchmark debate. Implementing the utilitarian benchmark, which we see as ethically minimal and conceptually parsimonious, in two leading climate-economy models allows for calculation of the optimal allocation of future emissions. We compare this optimum with historical emissions and initial nationally determined contributions. Compared with cost minimization, utilitarian optimization features better outcomes for human development, equity and the climate. Peak temperature is lower under utilitarianism because it reduces the human development cost of global mitigation. Utilitarianism therefore is a promising inclusion to a set of benchmarks for future explorations of climate equity.

Mere Addition is equivalent to avoiding the Sadistic Conclusion in all plausible variable-population social orderings.

Economic policy evaluations require social welfare functions for variable-size populations. Two important axioms in the population ethics literature are Mere Addition and avoidance of the Sadistic Conclusion, both of which focus on the sign of lifetime utility. The population ethics literature treats these axioms as closely related but distinct: one influential review calls avoidance of the Sadistic Conclusion "less controversial." Here, we provide weak, uncontroversial sufficient conditions for these two principles to be equivalent. Related results exist in prior literature, but these include only same-number utilitarian orderings and therefore exclude recent and theoretically important rank-dependent social evaluations that we include. [100 words].

Exposure to open defecation can account for the Indian enigma of child height.

Physical height is an important measure of human capital. However, differences in average height across developing countries are poorly explained by economic differences. Children in India are shorter than poorer children in Africa, a widely studied puzzle called "the Asian enigma." This paper proposes and quantitatively investigates the hypothesis that differences in sanitation - and especially in the population density of open defecation - can statistically account for an important component of the Asian enigma, India's gap relative to sub-Saharan Africa. The paper's main result computes a demographic projection of the increase in the average height of Indian children, if they were counterfactually exposed to sub-Saharan African sanitation, using a non-parametric reweighting method. India's projected increase in mean height is at least as large as the gap. The analysis also critically reviews evidence from recent estimates in the literature. Two possible mechanisms are effects on children and on their mothers.

Persisting Prejudice: Measuring Attitudes and Outcomes by Caste and Gender in India.

Nearly seventy years after India adopted one of the most progressive constitutions in the world ensuring equality for all its citizens irrespective of caste, class, race, and gender, the mind-set of its vast majority Indian remains steeped in gender and caste bias. Results from a new telephonic survey confirm persistence of conservative gender and caste attitudes in Indian society. High proportions of men and women across all social groups disapprove of women working outside their homes, consider it 'acceptable for husbands to beat their wives', and would object to relatives marrying a Dalit person. Analyzing data from the National Family Health Survey and the India Human Development Survey, it has been found that outcomes associated with these attitudes are even more conservative: a smaller fraction of women work than those who feel it is okay to step out of the house for work; a larger fraction of women experience violence in marriage than men who consider marital violence acceptable, and an even smaller fraction of people have inter-caste marriages than people who say they would not oppose such an alliance. An overwhelming majority is opposed to an inter-caste marriage with a Dalit in the family. With a few exceptions, the attitudes and outcomes we studied vary, surprisingly, little by respondent gender, caste, and religion. Dr.Ambedkar's legacy is indeed unfinished-people from all backgrounds must continue to work for the equality and dignity of women and Dalits.

Assessing high-profile public messaging for sanitation behaviour change: evidence from a mobile phone survey in India.

The UN Sustainable Development Goals call for the elimination of open defecation by 2030. Assessing global progress will require learning from India's sanitation efforts because of its ambitious program of high-profile behavior change messaging to tackle open defecation, and because open defecation is widespread in India. In 2014, the Prime Minister announced a policy called the Swachh Bharat Mission (SBM), which aimed to eliminate open defecation by 2019. However, the 2015-16 National Family Health Survey -4 found that about 55% of rural and 11% of urban Indian households lack a toilet or latrine. To assess the extent of public awareness of the SBM, we use a mobile phone survey to ask about people's knowledge of the existence and purpose of the SBM. We report representative estimates of awareness of the SBM among adults in Delhi (2016), Uttar Pradesh (2016), Mumbai (2016-17), Rajasthan (2016-17), Bihar (2018), Jharkhand (2018), and Maharashtra (2018). While much of the SBM's activities took place in its last two years, we find that, at the time of the survey, no more than one-third of adults in any state are aware that the SBM intends to promote toilet and latrine use. Awareness was particularly low in Uttar Pradesh, where one in eight people who defecates in the open worldwide lives. While the SBM was very active in constructing latrines, the lack of awareness we find suggests that the SBM was less successful in raising the awareness required for large-scale behavior change in promoting latrine use.