Sex preference versus number preference: the case of Korea

The author argues that the effect of sex preference must be disentangled from the effect of number preference in Korea. This study tests--with hazard models--the effect of the number of previous children on the next birth according to the sex composition of previous children. Data were obtained from the 1974 Korean Fertility Survey. This paper also analyzes the timing of childbearing in recent periods in order to determine whether replacement-level fertility is temporary or permanent. The ideal number of children declined from 3.9 children in 1965 to 2.1 in 1991. The age-specific fertility rates for ages 20-24 years declined rapidly during the late 1980s. The fertility rates among women aged 25-29 years and 30-34 years increased during 1985-90. The proportion of fertility among women aged 20-29 years increased from 67.9% in 1975 to 86.6% in 1984. Women born in the late baby boom period of the late 1950s to mid-1960s reached prime reproductive age during the late 1980s and 1990s, but the crude birth rate remained about the same during 1985-92. A higher percentage of women (22.4%) born during 1955-59 remained single in 1990. During 1960-90, the percentage of women aged 20-24 years who were married declined. These trends indicate later age at childbearing and an explanation for the temporary nature of below-replacement fertility in the late 1980s. Korean women did not want to have more than 2 children, and the interval between first and second births increased since 1985. Among pregnancies of parity 2 conceived since 1985, over 90% of women with at least one son ended subsequent pregnancies by abortion compared to only 59% without sons. Hazard models of 1974 data reveal that son preference had an important effect on fertility. Fertility was higher among women with only daughters. Findings suggest that the value of sons must be measured at the societal and not at the individual level.     

Marriage selection and age patterns of mortality: a mathematical investigation

"In this paper, we use simulation models to demonstrate the complexity of the relationship between the marriage selection process and the resulting RMRs [relative mortality ratios]. In particular, we show that marriage selection alone can produce a relative mortality ratio which remains large and relatively constant at ages far beyond the marriage span....Our general objective...is to determine the range of age patterns of relative mortality which could, in theory, result from marriage selection on the basis of health characteristics. We also evaluate the effects of variations in the marriage selection mechanisms on the resulting mortality patterns....We develop and apply several simple mathematical models of the marriage selection process. In order to distinguish the potential consequences of marriage selection from marriage protection, we consider hypothetical populations in which causal effects are absent....We begin by considering an extremely simple marriage selection process and subsequently explore a more realistic selection model based on recent death and marriage rates for Japan."     

Immigration and ethnic origin: the effect of demographic attributes on earnings of Israeli men and women

"The present article examines the separate effects of ethnicity and immigration on earnings by studying a sample of Israeli workers. The results indicate that immigrant status constitutes a major handicap in the Israeli labor market. Ethnicity, on the other hand, plays a minor role in the earnings determination process. The consequences of these results for labor market policies are discussed."     

Major obstacles to control of irregular migrations: prerequisites to policy

This paper examines 3 basic obstacles thwarting all attempts to reduce irregular migration. The 1st, rather well known and analyzed, underscores the dependency of all regulation of migratory flows on the system of economic and political relations between developed and developing countries. The 2nd obstacle resides in the persistance and growth of subsequent dependent irregular migration. This obstacle also reveals the relative autonomy of population movements compared with the employment situation in the labor market. The 3rd generally ignored obstacle is the role played by migration itself, particularly the discriminatory status of foreign workers in the labor market, in producing irregular migration.     

Perceived morbidity, utilisation of health services and factors affecting it in a rural area

A survey of perceived morbidity was carried out in rural population in eight villages and four wards of Saoner town, covering a total population of 8,876. The nature of illness was assessed by weekly visits to the families. History regarding treatment taken for disease and its source was taken. The overall incidence of perceived morbidity was 176.35 spells of sickness per 1000 population per month. Health care agency was contacted for 36.7 per cent spells of sickness. Utilisation of health services was found to be affected significantly by factors like age (chi 2 = 138.36), literacy (chi 2 = 14.123), type of occupation (chi 2 = 433.74), nature of illness (chi 2 = 83.578) and accessibility of health services. A health behaviour model of the population has also been discussed in this paper.     

On some characteristics of China's population--analysis of the ten percent sampling tabulation of the 1982 third national population census

Advance results from the 1982 census of China are presented based on a 10 percent sample. Sections are included on age distribution, centenarians, marriage patterns, educational status, and the labor force. Several characteristics of China's population are described in this article, based on a 10% sampling tabulation of the production teams and resident groups of the whole country. Data are included for 100,380,000 people. The proportion of the population aged 0-14 is 33.60%, which marks a decline from figures in the 1964 census (40%). This decline is attributed to family planning and population control efforts. The median age is 22.91 years, which is 2.71 years older than that in the 1964 census. The % of the population aged 15-64 rose from 55.7% in 1964 to 61.5%. The dependency ratio dropped from 79.4% (1964) to 62.6%. There were 3,765 centenarians as of July, 1982; the overwhelming majority live in villages, and most (94.77%) are illiterate or semiliterate. The number of female centenarians is 2.4 times that of males. Marriages are comparatively stable in China. 63.6% of the population aged 15 and over are married, and .59% are divorced. The % of the population remaining single after age 50 is .21% for females, 2.97% for males. The average 1st marriage age is 22.80 years for females and 25.49 years for males. 60.35% of the people have had primary education or above; .44% are college graduates. In 1964, 33.58% of the population illiterate or semiliterate. At present, among people aged 12 and over, 31.90% are illiterate or semiliterate. The rural illiteracy rate is more than twice the urban rate. 51.94% of the total population is employed. Of these, 92.08% are engaged in manual labor. Males exceed females in all professions and occupations. The median age of the employed population is 30.84 years. The level of education among the employed is relatively low: 28.26% are illiterate or semiliterate, and 34.35% have had primary education only.     

Solving the part families problem in discrete-parts manufacture by simulated annealing

In the production planning and control of discrete-parts manufacture, aggregation of parts into families, on the basis of similarity, is carried out to ease both long-horizon planning and short-horizon scheduling. Additional advantages are related to those of group technology (GT), such as simplifying the flow of parts and tools and reducing both set-up and production costs. The problem of formally forming part families is presented and discussed. Previous work is reviewed and assessed. Two solution approaches, one based on a location model, the other on simulated annealing, are presented and compared along with test results. The location formulation, which results in an integer programming model solved by Lagrangian relaxation, proved capable of producing solutions of excellent quality, but only for relatively small problem instances. In contrast, simulated annealing, which is a general heuristic approach to combinatorial optimization, produced solutions of comparable quality and could handle realistically large problem instances. However, careful design of the simulated annealing algorithm is crucially important. An effective design is presented.