[Review of] G.M.K. Kpedekpo. Essentials of Demographic Analysis for Africa

Based on lecture notes used by Kpedekpo at a number of African universities, this textbook for undergraduates provides an introduction to techniques of demographic analysis. Its twelve chapters are broad in coverage and address such topics as sources of population data; rates of fertility, mortality, and population growth; age and sex standardization; life table analysis; marriage and nuptiality; internal and international migration; methods for projecting population size and structure; stable and quasi-stable population theory; and methods for coping with deficient data. Numerous tables, charts, and worked examples help to illustrate demographic principles and techniques. An index is also included

Residential Segregation and Interracial Friendship in Schools

This article uses social network and spatial data from the National Longitudinal Study of Adolescent Health (Add Health) to examine the effect of racial residential segregation on school friendship segregation in the United States. The use of hierarchical models allows the authors to simultaneously estimate the effects of race, within-school residential segregation, and school diversity on friendship choice using the Add Health data. The authors use these results to predict the decline in friendship segregation that would occur if across- and within-school residential segregation were eliminated in U.S. metropolitan areas. The results suggest that about a third of the level of racial friendship segregation in schools is attributable to residential segregation. Most of this effect is the result of residential segregation across schools rather than within them

Simulated village locations in Thailand: a multi-scale model including a neural network approach

The simulation of rural land use systems, in general, and rural settlement dynamics in particular has developed with synergies of theory and methods for decades. Three current issues are: linking spatial patterns and processes, representing hierarchical relations across scales, and considering nonlinearity to address complex non-stationary settlement dynamics. We present a hierarchical simulation model to investigate complex rural settlement dynamics in Nang Rong, Thailand. This simulation uses sub-models to allocate new villages at three spatial scales. Regional and sub-regional models, which involve a nonlinear space-time autoregressive model implemented in a neural network approach, determine the number of new villages to be established. A dynamic village niche model, establishing pattern-process link, was designed to enable the allocation of villages into specific locations. Spatiotemporal variability in model performance indicates the pattern of village location changes as a settlement frontier advances from rice-growing lowlands to higher elevations. Experiments results demonstrate this simulation model can enhance our understanding of settlement development in Nang Rong and thus gain insight into complex land use systems in this area

Networks and Contexts: Variation in the Structure of Social Ties

A core axiom of sociology is that social structure affects and is affected by human behavior. The term "social structure" conveys two quite different meanings. One meaning is relational, involving networks of ties between individuals or groups of individuals. A second meaning refers to the contexts containing these individuals. Studies of neighborhood and community effects depend on variability in both types of social structure. Using data from multiple villages in Nang Rong, Thailand, this article documents substantial variability in network structure and shows that network structure covaries with context in meaningful ways, suggesting reciprocal effects of changes in both. Finally, it considers implications of variability in network structure, showing that social cohesion affects the likelihood of finding and interviewing former village residents

Social and spatial networks: Kinship distance and dwelling unit proximity in rural Thailand

We address a long hypothesized relationship between the proximity of individuals' dwelling units and their kinship association. Better understanding this relationship is important because of its implications for contact and association among members of a society. In this paper, we use a unique dataset from Nang Rong, Thailand which contains dwelling unit locations (GPS) and saturated kinship networks of all individuals living in 51 agricultural villages. After presenting arguments for a relationship between individuals’ dwelling unit locations and their kinship relations as well as the particulars of our case study, we introduce the data and describe our analytic approach. We analyze how kinship - considered as both a system linking collections of individuals in an extended kinship network and as dyadic links between pairs of individuals -patterns the proximity of dwelling units in rural villages. The results show that in general, extended kin live closer to one another than do unrelated individuals. Further, the degree of relatedness between kin correlates with the distance between their dwelling units. Close kin are more likely to co-reside, a fact which drives much of the relationship between kinship relatedness and dwelling unit proximity within villages. There is nevertheless suggestive evidence of a relationship between kinship association and dwelling unit proximity among kin who do not live together

Population growth and its spatial distribution as factors in the deforestation of Nang Rong, Thailand

Frontiers constitute a major source of global land cover change hot spots, with forests and grass lands being converted into agricultural uses. As such, frontiers provide an opportunity to see how people manipulate the land and their lives in the context of social, cultural and environmental constraints. This paper examines frontier settlement and land cover change in Nang Rong district, Northeast Thailand for the last half century. It uses a Cellular Automata (CA) model to explore the land cover consequences of alternative patterns of settlement in a setting where people establish dwelling units in nucleated villages and work agricultural plots that surround villages. Forested land around the center of a village is converted into agricultural uses in an inverse relationship to the distance from the village center, but frequently modified by biophysical conditions. Land at the center of the village may be reforested after the village is established as a source of shade as well as fruit and other products. Model variation in land cover change is more sensitive to the spatial reach of village households than their temporal reach, suggesting the important role that technology plays in how villagers travel to their fields (walking versus motorized transit)

Recruitment of Women in the National Children's Study Initial Vanguard Study

The initial Vanguard Study of the National Children's Study was conducted during 2009–2010 in 7 locations in the United States. A goal was to evaluate the feasibility and yield of a household-based sampling design to recruit pregnant women. A multistage area probability sampling design was used to identify study locations (generally, counties) that were subsequently divided into smaller geographical units, termed segments. Between 7 and 18 segments were selected in each location, and dwelling units within segments were listed. A household-based recruitment process was implemented, which included enumeration of households to identify age-eligible women, pregnancy screening to identify pregnant women eligible for immediate enrollment and nonpregnant women for telephone follow-up, and administration of informed consent to eligible women. After a recruitment period of 17–20 months, 67,181 (89%) households were enumerated, which identified 34,172 (88%) age-eligible women to whom the pregnancy screener was administered. Among those who completed the screener, 2,285 women became eligible for enrollment, of whom 1,399 (61%) enrolled. Although response rates were fairly high at initial contact and among pregnant women, the overall yield was lower than anticipated. In particular, telephone follow-up of nonpregnant women was not a practicable strategy for prospective recruitment of newly pregnant women

Climate shocks and migration: an agent-based modeling approach

This is a study of migration responses to climate shocks. We construct an agent-based model that incorporates dynamic linkages between demographic behaviors, such as migration, marriage, and births, and agriculture and land use, which depend on rainfall patterns. The rules and parameterization of our model are empirically derived from qualitative and quantitative analyses of a well-studied demographic field site, Nang Rong district, Northeast Thailand. With this model, we simulate patterns of migration under four weather regimes in a rice economy: 1) a reference, ‘normal’ scenario; 2) seven years of unusually wet weather; 3) seven years of unusually dry weather; and 4) seven years of extremely variable weather. Results show relatively small impacts on migration. Experiments with the model show that existing high migration rates and strong selection factors, which are unaffected by climate change, are likely responsible for the weak migration response

Changing crops in response to climate: Virtual Nang Rong, Thailand in an agent based simulation

The effects of extended climatic variability on agricultural land use were explored for the type of system found in villages of northeastern Thailand. An agent based model developed for the Nang Rong district was used to simulate land allotted to jasmine rice, heavy rice, cassava, and sugar cane. The land use choices in the model depended on likely economic outcomes, but included elements of bounded rationality in dependence on household demography. The socioeconomic dynamics are endogenous in the system, and climate changes were added as exogenous drivers. Villages changed their agricultural effort in many different ways. Most villages reduced the amount of land under cultivation, primarily with reduction in jasmine rice, but others did not. The variation in responses to climate change indicates potential sensitivity to initial conditions and path dependence for this type of system. The differences between our virtual villages and the real villages of the region indicate effects of bounded rationality and limits on model applications

Migrant remittances and the web of family obligations: Ongoing support among spatially extended kin in North-east Thailand, 1984–94

Exchanges of money, goods, and assistance among family/kin members are influenced by the intertwined lives of individuals and their family/kin. As people pass through the young adulthood years, acquiring obligations as spouses and parents, and migrating in search of economic opportunities, tensions can arise over existing obligations. Using rich longitudinal data from Northeast Thailand, we examined the role of family networks (origin and destination) on migrants’ exchanges with family/kin. Our approach overcame many shortcomings of earlier studies, allowing us to 'see' the family social network arrayed in a broader network. We show that intra-family exchanges are influenced by marital status, the presence of children, having parents in the origin household, and having siblings depart from it. The results are stable across sensitivity tests that systematically include or exclude various familial links. And reports provided by origin households on migrant remittances are consistent with reports from migrants themselves