On tests for sex preferences

This paper presents a critical evaluation of three widely used tests for sex preferences: sex ratio, parity progression ratio and ordinary least squares regression of birth interval. We show that under some appropriate conditions, the sex ratio is a valid test for sex preferences. The methods of parity progression ratio and OLS regression of birth interval fail to deal with right censoring and time varying covariates, which reduce the power of the tests. We suggest the use of hazard estimation to test for sex preferences. We demonstrate the differences among the tests by analyzing the retrospective fertility histories of the Chinese and the Malays in Malaysia. We find that unlike the two conventional methods, the hazard estimation gives clear and strong evidence of sex preferences among the Chinese in Malaysia.I am indebted to Gary Becker, James Heckman and Thomas Mroz for their many valuable comments and encouragement. I have also benefited from the discussions with V. Joseph Hotz, Mark Rosenzweig, Lester Telser and Robert Willis. Research support from the Bradley Foundation and the Hewlett Foundation is gratefully acknowledged. Computational facilities are supported by NICHD Grant HD-19226 and NSF Grant SES-84-11242 to the Economics Research Center/NORC.     

A dispersal-aggregation model for mountain pine beetle in lodgepole pine stands

Summary In this paper a dispersal-attack theory for bark beetle attacking trees is developed from a set of simple assumptions, and the resulting theoretical model is fit to data from four epidemic studies. Implications of the theory are discussed in relation to the dynamics of lodgepole pine-mountain pine beetle interactions. Scientific paper #4632, Project #102, College of Agriculture Research Center, Washington State university, Pullman, Washington. The work reported herein is the result of cooperation between scientists at Washington State University, the University of Idaho, and the U.S. Forest Service, and is supported by the National Science Foundation (Grant No. GB-341728), through contract SC 0024 with the University of California (Berkeley). The opinions expressed herein are not necessarily those of California or NSF.     

Beliefs and values and the sterilization decision

A decision-making framework based on the models of personal decision making developed by psychologists and economists and a methodology based on axiomatic conjoint measurement are used to explore individuals' beliefs and values regarding contraceptive sterilization. Particular emphasis is given to demonstrating a. that there exist individual differences in beliefs and values, b. that there exist differences in beliefs and values between persons who choose sterilization—either tubal ligation or vasectomy—and persons who choose non-sterilization contraceptive methods when no more children are wanted, and c. that the effect of beliefs and values on the sterilization decision is an interactive one. The methodology used is compared to that typically used in studying fertility- and health-related behaviors.This research was supported by grants HD-10802 and HD-14403 from the National Institute of Child Health and Human Development. The technical assistance of Doreen Victor and the editorial suggestions of Sarah Gaskill, Alice Healy, and two anonymous reviewers are greatly appreciated. This paper is Publication No. 253 of the Center for Research on Judgment and Policy, University of Colorado, Boulder, CO 80309-0344. Requests for reprints should be sent to the Publications Librarian at the Center.     

Advantages and disadvantages of pregnancy and contraception: Teenagers' perceptions

Research has shown that teenagers' perceptions of the advantages and disadvantages of pregnancy and contraception are significant predictors of pregnancy risk taking. This analysis examines the content and determinants of these cost-benefit sets, using data from 425 sexually active adolescents. The results indicate that teens' perceptions of the advantages and disadvantages of pregnancy and contraception are neither strongly nor systematically related to each other. Moreover, the determinants of the four cost-benefit sets are varied, although there is some overlap between sets. Explanations of these findings and implications for future research and for the delivery of family planning services to teenagers are suggested.The authors names are listed alphabetically. The work reported herein was supported by an NICHD grant No. 1 R01-HD-1485-01. Direct all communication to Debra Kalmuss, Center for Population and Family Health, Columbia University, 60 Haven Avenue, New York, N.Y. 10032.     

The effect of public policies on recent Swedish fertility behavior

In the literature the recent upsurge in period birth rates is seen as evidence of a pronatalist effect of Sweden's extensive social insurance programs. Yet, these explanations can not account for the downturn in birth rates in the 1970s, the delay in childbearing, and the constancy of cohort birth rates which characterize recent Swedish fertility behavior. To summarize the effect of Sweden's economic and policy environment on the observed fertility patterns, I use a neoclassical economic framework to develop the shadow price of fertility. Although strong simplifying assumptions are imposed, the estimated price series exhibit a negative relationship with period fertility rates and the change in the estimated relative prices of fertility over the life cycle lend modest support for the delayed childbearing.The first draft of this paper was written while I was a National Fellow at the Hoover Institution. The research was supported by grants number HD-19226 and HD-28685 from the National Institute of Child Health and Development. I thank Glen Cain, John Kerman, Tom MaCurdy, Duncan Thomas, Michael Tilkin, and seminar participants at University of Illinois, Hoover Institution, and University of Wisconsin for useful comments.     

Will sex selection reduce fertility?

This paper investigates both theoretically and numerically the impact of sex selection on fertility. A static quantity-quality model of fertility is employed to compare fertility choices in two regimes: one in which parents cannot choose the gender of children and another in which parents can fully choose the gender of children. The static theory shows that whether sex selection reduces fertility depends on the second and third derivatives of the utility function and the child expenditure function. A numerical dynamic analysis is also presented. Using empirical dynamic models of fertility and Monte Carlo integration technique, the simulation shows that sex selection on the firstborn child among the Chinese in Malaysia could reduce fertility by about 3%.I thank the referees for their comments. I am indebted to James Heckman for providing generous computing support. Computational facilities were funded by NICHD Grant HD-19226 and NSF Grant SES-84-11242 to the Economics Research Center, NORC.     

Subjective utility and plans for childbearing and employment

Nonrecursive models of plans for childbearing and employment were estimated for a sample of white married women, age 26 to 36, with one or two young children. Women's concerns about care of children already born did inhibit their employment plans. Further, plans to have another child in the near future had a direct negative effect on full-time employment plans among women with one child, but not among women with two children. No direct effects of childbearing plans on part-time employment plans were found. In contrast to earlier research on longterm childbearing and employment plans, no direct effects of employment plans on plans for childbearing were found. It is suggested that attainment of the two-child family marks a turning point in the relation between childbearing and wives' employment.This research was partially supported by grants from the Center for Population Research, NICHD to Battelle Human Affairs Research Centers, Seattle, Washington (1-R01-HD10683), and to the Center for Demography and Ecology, University of Wisconsin, Madison (1-R01-HD05876). I wish to thank Andrew R. Davidson for the opportunity to conduct the research. I am also grateful to Pamela Oliver, Larry Bumpass, and the two anonymous reviewers for their constructive comments on earlier versions of this article.     

Parity and the expected consequences of childbearing

In this study 163 young married women with 0, 1, or 2 children described the advantages and disadvantages of having a (another) child in the next three years and the expectations of significant others regarding their childbearing behavior. Childless women were more likely than women at first and second parity to mention self-fulfillment, pleasing parents, strengthening their marriage, less time and freedom, interference with career and education, being emotionally unprepared, and creating friction in their marriage. Women with one child were most likely to mention companionship and achieving family size goals. For women with two children gender preference and less time for present children were particularly salient consequences. Women with one child report experiencing the strongest pronatalist normative pressures but the perceived preferences of significant others were most closely related to own childbearing plans for childless women. The results are discussed in terms of a parity specific approach to the study of motivations for parenthood.The research reported here was supported by Grant HD 10391-01, Center for Population Research, National Institute of Child Health and Human Development. Robyn Boyer is now an independent research consultant in Sacramento, California. Requests for reprints should be addressed to Thomas J. Crawford, Program in Social Ecology, University of California, Irvine, California, 92717.     

Measuring fertility norms

We argue that social norms must be measured at the group level of analysis, allow for a range of acceptable behaviors, and be linked to the individual level of analysis to explain social behavior. From a survey of young adults in Wisconsin (1973), we generated measures of family size norms from sibship experience and friends' expected family size. These measures satisfied our primary criterion for a social norm: Those with non-normative family size desires tended to shift expectations toward the norm. The analyses demonstrate the difficulty of estimating normative effects when by its very definition a norm is expected to restrict variation in human behavior.Revision of a paper presented at the annual meetings of the American Sociological Association, New York, New York, August 30–September 3, 1986. This research was supported by Grant 1-R01-HD-17190 and by Center Grant HD05876 from the Center for Population Research, NICHHD. Paula Goldman's work was supported by Training Grant 5732HD07014 from the same source.     

Towards a theory of insect epidemiology

Summary An attempt is made to consolidate and extend some of our current thoughts on insect epidemiology using graphical reproduction models. Starting with a simple model with a single equilibrium point, the elementary hypothesis is proposed that epidemics erupt when this equilibrium point increases substantially through improvement of the insect's habitat. The extension of this model to more than one coincident equilibria, some of which may be locally stable, is discussed and generalized using the theory of habitat suitability. Use of equilibrium manifolds is suggested to permit greater dimensionality. Lastly, an explanation of insect epidemics, based on the effects of time delays in the response of density-dependent processes, is elaborated and generalized. The influence of spatial dimensions and insect dispersal on the theory is discussed. Scientific Paper No. 4890, College of Agriculture Research Center, Washington State University. Modified from a paper presented at the joint meeting of the Sociedad Mexicana de Entomologia and the Pacific and Southwestern Branches of the Entomological Society of America, held at Guadalajara, Mexico, April 17–22, 1977. This work was conducted under Project 102 and was supported by the State of Washington and the National Science Foundation (Grant Nos. GB-30752 and GB-34718).     

Family planning practice and women's fertility decision-making power

This paper investigates the effects of family planning practice on fertility decision-making power in South Korea. The log-linear analysis of the 1981 survey data by the Institute of Population and Health Services Research, Yonsei University, Seoul, Korea, shows that those urban and rural women who practice family planning or have experienced abortion exercise greater influence on a couple's fertility decision making than those who do not practice family planning or who have had no abortion experience. In addition, there is the interactive effect of abortion experience and contraceptive use on fertility decision making among urban women. This finding is significant because regardless of how birth control is available within a society, birth control use enhances women's decision making power where fertility is concerned.     

第五届数字中国发展高层论坛暨信息主管峰会“数字健康论坛”在京举行

2008年12月7—8日,由北京大学数字中国研究院和中国人口与发展研究中心主办、中国标准化研究院人口与健康信息技术研究中心和中国仪器仪表学会医疗仪器分会电子健康专业委员会协办的“数字健康论坛”在北京大学举行。此次论坛是北京大学和国际数字地球学会联合主办的“第五届数字中国发展高层论坛暨信息主管峰会”的分论坛,主题为电子信息与空间技术在人口与健康领域的应用。     

Incorporating husband-wife differences in place utility differentials into migration decision models

This paper extends the micro-level empirical literature on migration decision making by investigating the manner in which husbands' and wives' subjective place utility expectations jointly feed into migration decisions in a low-income country. The authors use expectational data relating to four place utility dimensions and stated migration intentions of 376 village-resident Egyptian couples to test alternative decision models. An ordinal probit estimation technique is employed. The results of the analyses support the hypothesis of husband dominance in migration decisions in this context. The authors conclude with a discussion of the implications of the paper for further theoretical refinement and for migration survey design in this and other developing countries.Dr. McDevitt is a Research Associate of the Carolina Population Center, The University of North Carolina at Chapel Hill. Dr. Gadalla, former Director of The Social Research Center of The American University in Cairo, is currently Visiting Distinguished Professor of Sociology-Demography, San Diego State University, San Diego.This is a revised version of a paper presented at the 1984 annual meetings of the Population Association of America and cited throughout as McDevitt and Gadalla (1984). The authors wish to acknowledge helpful discussions with Amos Hawley in the early stages of the development of the paper and the guidance of David Guilkey and Larry Taylor with the statistical techniques employed in the work reported in the paper. The research was supported in part by grants 1-R01-HD14943 and 1-T32-HD07168 from the National Institutes of Health.     

The effect of maternal employment on teenage childbearing

This paper estimates the effect of a mothers employment on her teenage daughters likelihood of birth. Using data from the United States, the National Education Longitudinal Survey of 1988, the author finds that teenagers with working mothers who attend relatively wealthy schools are more likely (77%) to have a birth compared to teens who attend similar schools but have non-working mothers. In contrast, teenagers with working mothers who attend relatively poor schools are less likely (18%) to have a birth compared to teens who attend similar schools but have non-working mothers.I am indebted to Marcia Carlson, Thomas DeLeire, Angela Fertig, Brian Jacob, Darren Lubotsky, Scott Lynch, Susan Mayer, Sara McLanahan, Robert Michael, German Rodriguez, seminar participants at Princeton University and The University of Chicago, and two anonymous referees for insightful suggestions made on earlier versions of this paper. I also gratefully acknowledge financial support from a Northwestern University/University of Chicago Joint Center for Poverty Research Graduate Fellowship, a Robert R. McCormick Tribune Foundation Graduate Fellowship, the Bendheim-Thoman Center for Research on Child Wellbeing at Princeton University, and the Office of Population Research at Princeton University, which is supported by center grant 5 P30 HD32030 from the NICHD. Responsible editor: Junsen Zhang.     

Family planning's benefits include improved child health and nutrition: new data from Bangladesh

2 recent studies from the Matlab in Bangladesh confirm that family planning promotes child survival. The 1st study is a longitudinal analysis of 3370 births in 1985 to women living in 70 villages who were served by the International Centre for Diarrhoeal Disease Research, Bangladesh's Matlab Family Planning and Health Services Project. The 2nd is a study of 12-26 month old children and 24-36 month old children, all of whom were born in the same 70 villages between July 1985 and June 1986. The 1st study demonstrates that family planning improves child survival by lengthening the birth interval. In fact, if women delay a subsequent birth by about 2 years, child survival improves at all ages up to 5 years. Longer birth intervals result in a reduction of very high order births. The same study also reveals that family planning improves child survival indirectly by granting mothers access to integrated maternal and child health services. The 2nd study indicates that a child is 3 times more likely to suffer malnutrition, even at age 3, than a child whose mother gives birth again at an interval greater than 24 months. Specifically, the mother removes the index child from the breast prematurely, thereby adversely affecting the index child's nutrition. The birth interval prior to the index child does not adversely affect the index child's nutritional status, however. The 2nd study's result suggest that birth spacing, as promoted by family planning programs, improves child health and nutrition. The findings from these studies show the importance of continued investments in family planning programs in developing countries.     

The effect of normative pressures on fertility

Using longitudinal data from a sample of urban, white, married U.S. couples, this paper shows the effects of normative pressures from family and friends on whether or not the couple had a pregnancy within one year. A comparison of parity-specific and all-parity models indicates that more information and better predictions can be obtained from parity-specific models. Normative pressures predict pregnancy best at zero parity, with progressively attenuated predictions at higher parity. A comparison of models using husband and wife data together shows that two-sex models are better than models using either sex alone. In a variety of different models, normative pressures reported by husbands are better predictors of pregnancy than are normative pressures reported by wives. A comparison of models using aggregated measures of normative pressures with models identifying the separate individual sources of pressures indicates that each treatment provides different insights into the effects of normative pressures, but that predictive power is lost through aggregation.This study was supported by a grant from the Center for Population Research, NICHD (Grant No. N01-HD-42804). Boone Turchi and Karl Bauman were collaborators on the original study. The authors would like to thank Judy Kovenock for data analysis. Requests for reprints should be directed to J. Richard Udry, Carolina Population Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514.     

Bayesian analysis of an econometric model of birth inputs and outputs

This study offers a simultaneous equations model of the birth process with seven endogenous variables: four birth inputs (maternal smoking, maternal drinking, first trimester prenatal care, and maternal weight gain) and three birth outputs (gestational age, birth length, and birth weight). The data are taken from the National Longitudinal Survey of Youth. Our analysis conditions on twenty-nine exogenous variables including four racial dummies to account for the widely cited racial differences in birth outputs. We find that there is sizeable correlation between the disturbances in the four input and three output equations and among output disturbances, and that results from our simultaneous equations model are substantially different from those using the single-equation approach. It appears that the High/Low Risk Birth Weight Puzzle remains unresolved under our modeling framework.All correspondence to Kai Li. The authors gratefully acknowledge the research support of the Social Sciences and Humanities Research Council of Canada, and helpful comments on an earlier draft by the editor (Junsen Zhang), two anonymous referees, Sid Chib, Kei Hirano, John Geweke, Gary Koop, seminar participants at the University of Alberta, the University of California at Irvine, University of Kansas, University of Minnesota, Queen Mary College of University of London, Washington University at St. Louis, and participants of the 2001 Winter Meetings of the Econometric Society in New Orleans. We are solely responsible for any errors contained herein. Responsible editor: Junsen Zhang.     

Residential preferences in a model of migration intentions

The congruence of stated residential preferences and observed migration behavior suggests that preferences may be important in the migration decision-making process. Using data from the March 1974 NORC Amalgam Survey, this analysis incorporates a measure of residential preference into a model of migration intentions similar to that developed by Speare (1974) for residential movement. Our results indicate that preferences and community satisfaction are interrelated and each has an independent effect on migration. We also find that the decision to migrate may be more directly influenced by ties to the community than is a residential move. Thus home ownership, age, and length of residence directly affect migration plans net of preferences and satisfaction, whereas only home ownership directly influenced the decision to move residentially in Speare's (1974) analysis.This research has been supported by the Minnesota Agricultural Experiment Station (Journal Article #10,961), and by the Economic Development Division, Economic Statistics, and Cooperatives Service, U.S. Department of Agriculture through a cooperative agreement with the College of Agricultural and Life Sciences, University of Wisconsin-Madison. Additional support was provided by the Michigan Agricultural Experiment Station, the College of Social Sciences, Michigan State University, and by the Center for the Study of Metropolitan Problems, NIMH. Computer analysis was aided by a "Center for Population Research" grant, No. HDO5876, to the Center for Demography and Ecology, University of Wisconsin-Madison, from the Center for Population Research of the National Institute of Child Health and Human Development. We wish to thank Dennis Hogan and Joel Nelson for comments on an earlier draft of this paper. James Zuiches is currently on leave from Michigan State University.     

Migration intentions and behavior: Decision making in a rural Philippine province

The relationship between intentions and behavior is basic to micro-level migration decision research. This study, set in the rural Philippine province of Ilocos Norte, provides evidence on personal and structural background factors and value-expectancy perceptions of place utility that predict migration intentions and behavior. Separate analyses are conducted for general intentions to move and for destination-specific migration intentions, the latter pertaining to both internal migration (Manila) and international migration (Hawaii). Logistic regression analyses applied to the data from a 1980–82 longitudinal survey show that the empirical models are highly efficient in explaining migration intentions but less efficient in explaining actual migration behavior in this Third World setting. Important explanatory variables for both intentions and behavior include family pressure to move or stay, family auspices at alternative destinations, money to move, prior migration experience, and the life cycle stage (marital status and age). However, the determinants of internal and international migration behavior are not the same. The data only partially support the Ajzen and Fishbein (1980) position that intentions are the dominant determinant of behavior. Personal and structural background factors are shown to exert independent direct effects on migration behavior.Revised version of a paper presented at the annual meeting of the Population Association of America, Minneapolis, Minnesota, May 2–5, 1984. Research for this paper was supported by NIH Grant No. R01-HD13115, the Population Center Foundation, The Philippines, the East-West Population Institute, Honolulu, Hawaii, and the Population Issues Research Center, University Park, PA. The other coinvestigators for this project are Fred Arnold, East-West Population Institute, and Benjamin V. Carino, University of the Philippines.     

Birth planning on many fronts: personal glimpses of innovations in China's Population Programme

The national birth planning program was initiated in 1965 in China with the establishment of a general office for family planning. Birth planning offices exist at the provincial, district, county, and municipal levels. Shanghai, in particular, is cited as 1 locale with a very active birth planning program with publicity campaigns and education reinforced by a national system of incentives. There is also a disincentive measure aimed at those with 2 children who have a 3rd--each parent must forfeit 10% of their monthly wage to the government. The ESCAP mission was told that few were expected to be so penalized since education and propaganda had become more efficient since 1974. Likewise, the province of Guangdong established an incentives/disincentives program with the guiding philosophy being that birth planning, education, ideology, and incentives exist in order to help solve practical problems. Once again in China the significance of population programs has been recognized and the study of population is being reinstituted in universities. The Chinese Academy of Sciences is developing a center for population research in Beijing along with an information center for the purposes of academic and applied research. Beijing University is creating a population studies program in the Economics Department with input from other departments. The municipality of Shanghai has established the Population Research Society while in Guangdong a similar such organization was established in September 1979, with areas of concentration in legal aspects of population change and zero population growth by 2000. Population studies is also being organized at Dr. Sun Yat Sen University and Jie-Nan University.