Migration and household demography in Nang Rong, Thailand

This work investigates various facets of migration and household demography in Thailand, a developing country that has been experiencing a shift from a rural subsistence economy to an urban industrial base. The setting is Nang Rong, a rural agrarian district located in Buriram province in the Northeast. At one time a frontier region, the district has been undergoing tremendous social, economic, and demographic transformations in the last three decades. The first analytical portion of the work deals with care for children of absent migrant parents. I develop a model of total childcare, whereby someone other than a biological parent assumes total parental responsibility in the parents' absence. I describe a process whereby a mutually-beneficial intergenerational household division of labor develops in which the older generation cares for the children of absent migrant parents, who provide for economic needs of their origin households. Next, using help with harvesting rice as an illustration of the profound changes that occur during the industrial transition, I examine intergenerational relations between young out-migrants and their parents. I find that migrants are more likely to help with the rice harvest if their origin household owns securely titled land, and if the migrant has lower human capital endowments. Results suggest that intergenerational relations between parents and children are becoming more instrumental, which is related to a household strategy predicated on individual self-interest and bargaining. The final analytical chapter deals with the effect of remittances on household division, a demographic process that is understudied in rural developing contexts. Results suggest that remittance money sent by other household members (especially women, who perhaps are siblings of those who eventually move) is used to finance a household split. This is potentially related to the effect that remittances have on alleviating credit constraints, which makes it possible for families and households to fund costs (such as home construction) associated with movement into an independent household. Remittance effects are particularly associated with a later stage in the Thai household life cycle whereby a young couple moves out of the household of the wife's family into an independent nuclear household

Migrant Remittances and Skipped Generation Households: Investigating the Exchange Motive Using Evidence from Nang Rong, Thailand

Using data from the Nang Rong projects social survey (N=6,801 households) and qualitative data from semi-structured interviews, I examine the relationship between migrant remittances and the skipped generation household structure. I find that the skipped generation household is a significant determinant of in-kind remittances and the amount of remittances received by the household. Surprisingly, although qualitative data suggest that grandparents living in skipped generation households provide childcare for the children of absent migrants, quantitative evidence reveals that these households receive lower remittance amounts than other households. This suggests that although an exchange motivation may be overlooked in the remittance literature, it does not apply to migrant remittances as it does in the broader literature on inter vivos intergenerational transfers.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Characterisation of the tetrahalophosphonium cations PBrnI4 − n+ (0 ≤ n ≤ 4) by 31P MAS NMR, IR and Raman spectroscopy and the crystal structures of PI4+AlCl4−, PI4+AlBr4− and PI4+GaI4−

The novel tetrahalophosphonium salts PBr4+AsF6−, PI4+AlCl4− and PI4+EBr4− (E = Al, Ga) have been synthesised. A variety of solid complexes containing PBr4+ (e.g. PBr4+AsF6−, PBr4+AlBr4− PBr4+GaBr4−), PI4+ (e.g. PI4+AlCl4−, PI4+AlBr4−, PI4+GaBr4−) or the mixed species PBrnI4 − n+ (0 ≤ n ≤ 4, containing AlBr4−, GaBr4−, AsF6− or SbF6−) have been studied by solid-state 31P MAS NMR and vibrational spectroscopy. The influence of the counter-ion on the chemical shift and the vibrational frequencies are discussed. The crystal structures of PI4+AlCl4−, PI4+AlBr4− and PI4+GaI4− are reported. Evidence for the existence of the hitherto unknown mixed bromoiodophosphonium cations PBr3I+, PBr2I2+ and PBrI3+ has been confirmed by spin–orbit corrected density functional calculations of isotropic 31P chemical shifts for PBrnI4 − n+

A boundary exchange influence on deglacial neodymium isotope records from the deep western Indian Ocean

The use of neodymium (Nd) isotopes to reconstruct past water mass mixing relies upon the quasi-conservative behaviour of this tracer, whereas recent studies in the modern oceans have suggested that boundary exchange, involving the addition of Nd from ocean margin sediments, may be an important process in the Nd cycle. Here we suggest that the relative importance of water mass advection versus boundary exchange can be assessed where the deep western boundary current in the Indian Ocean flows past the Madagascan continental margin; a potential source of highly unradiogenic Nd. Foraminiferal coatings and bulk sediment reductive leachates are used to reconstruct bottom water Nd isotopic composition (εNd) in 8 Holocene age coretops, with excellent agreement between the two methods. These data record spatial variability of ∼4 εNd units along the flow path of Circumpolar Deep Water; εNd≈−8.8 in the deep southern inflow upstream of Madagascar, which evolves towards εNd≈−11.5 offshore northern Madagascar, whereas εNd≈−7.3 where deep water re-circulates in the eastern Mascarene Basin. This variability is attributed to boundary exchange and, together with measurements of detrital sediment εNd, an isotope mass balance suggests a deep water residence time for Nd of ≤400 yr along the Madagascan margin. Considering deglacial changes, a core in the deep inflow upstream of Madagascar records εNd changes that agree with previous reconstructions of the Circumpolar Deep Water composition in the Southern Ocean, consistent with a control by water mass advection and perhaps indicating a longer residence time for Nd in the open ocean away from local sediment inputs. In contrast, sites along the Madagascan margin record offset εNd values and reduced glacial–interglacial variability, underlining the importance of detecting boundary exchange before inferring water mass source changes from Nd isotope records. The extent of Madagascan boundary exchange appears to be unchanged between the Holocene and Late Glacial periods, while a consistent shift towards more radiogenic εNd values at all sites in the Late Glacial compared to the Holocene may represent a muted signal of a change in water mass source or composition

Farming Systems and Rural Out-Migration in Nang Rong, Thailand, and Chitwan Valley, Nepal: Farming Systems and Rural Out-Migration

Using data from two post-frontier rural settings, Nang Rong, Thailand (N=2,538) and Chitwan Valley, Nepal (N=876), this paper examines agricultural push factors determining the outmigration of young people age 15 to 19. We focus on different dimensions of migration, including distance and duration. Our study examines a wide array of agricultural determinants, each with its own potential effect on migration. These determinants include land tenure, crop portfolios, animal husbandry activities, and use of farm inputs. We link these proximal causes to two underlying mechanisms: risk and amenities. We examine these determinants using separate models across settings. Our results indicate that agricultural factors are significant determinants of migration in both contexts. However, different factors operate in different settings, indicating the importance of contextual variation in explaining the manner in which risks and amenities influence agricultural determinants of migration

Marriage counterfactuals in Japan: Variation by gender, marital status, and time

Background: This paper takes a unique perspective on the debate surrounding the deinstitutionalization of marriage. Rather than examining how diversification of family behaviors (external context) relates to marriage, it considers how perceptions of marriage dimensions (the internal context) vary across relevant stakeholders. Objective: We ask whether perceived consequences of marriage differ for people who married vs. people who never married and men vs. women and over time. Methods: Based on data from the 1994 National Survey on Work and Family Life in Japan and the 2000 and 2009 National Survey of Family and Economic Conditions (NSFEC) in Japan (N = 8,467) we use unique measures of perceived consequences of marriage ("marriage counterfactuals") to examine social, economic, psychological, and personal dimensions (i.e., respect, living standard, emotional security, freedom, and overall satisfaction). Results: Ordinal regression results reveal that marital perceptions worsened over time (in terms of living standard and freedom), consistent with worsening economic conditions. We also find that people who have never been married tend to view marriage more favorably than their married counterparts (especially freedom and respect), while men view marriage consequences (except for living standard) more favorably than women. Conclusions: Despite more negative change over time in perceptions of marriage among people who never married than people who have married, the traditional breadwinner-homemaker model of marriage continues to be important and influential in Japan, and cultural beliefs regarding traditional marriage persist in spite of structural changes. Contribution: Research and theory on family change should pay more attention to the internal marriage context more fully than they have in the past

Reactivity of neodymium carriers in deep sea sediments: Implications for boundary exchange and paleoceanography

The dissolved neodymium (Nd) isotopic distribution in the deep oceans is determined by continental weathering inputs, water mass advection, and boundary exchange between particulate and dissolved fractions. Reconstructions of past Nd isotopic variability may therefore provide evidence on temporal changes in continental weathering inputs and/or ocean circulation patterns over a range of timescales. However, such an approach is limited by uncertainty in the mechanisms and importance of the boundary exchange process, and the challenge in reliably recovering past seawater Nd isotopic composition (εNd) from deep sea sediments. This study addresses these questions by investigating the processes involved in particulate–solution interactions and their impact on Nd isotopes. A better understanding of boundary exchange also has wider implications for the oceanic cycling and budgets of other particle-reactive elements. Sequential acid-reductive leaching experiments at pH ∼2–5 on deep sea sediments from the western Indian Ocean enable us to investigate natural boundary exchange processes over a timescale appropriate to laboratory experiments. We provide evidence that both the dissolution of solid phases and exchange processes influence the εNd of leachates, which suggests that both processes may contribute to boundary exchange. We use major element and rare earth element (REE) data to investigate the pools of Nd that are accessed and demonstrate that sediment leachate εNd values cannot always be explained by admixture between an authigenic component and the bulk detrital component. For example, in core WIND 24B, acid-reductive leaching generates εNd values between −11 and −6 as a function of solution/solid ratios and leaching times, whereas the authigenic components have εNd ≈ −11 and the bulk detrital component has εNd ≈ −15. We infer that leaching in the Mascarene Basin accesses authigenic components and a minor radiogenic volcanic component that is more reactive than Madagascan-derived clays. The preferential mobilisation of such a minor component demonstrates that the Nd released by boundary exchange could often have a significantly different εNd composition than the bulk detrital sediment. These experiments further demonstrate certain limitations on the use of acid-reductive leaching to extract the εNd composition of the authigenic fraction of bulk deep sea sediments. For example, the detrital component may contain a reactive fraction which is also acid-extractible, while the incongruent nature of this dissolution suggests that it is often inappropriate to use the bulk detrital sediment elemental chemistry and/or εNd composition when assessing possible detrital contamination of leachates. Based on the highly systematic controls observed, and evidence from REE patterns on the phases extracted, we suggest two approaches that lead to the most reliable extraction of the authigenic εNd component and good agreement with foraminiferal-based approaches; either (i) leaching of sediments without a prior decarbonation step, or (ii) the use of short leaching times and low solution/solid ratios throughout

Changes in Received Pronunciation: Diachronic Case Studies

This paper sets out to investigate changes and individual irregularities in the Received Pronunciation of a number of individuals over time and to compare them with the changes noted in contemporary RP in the literature. The aim of the study is to ascertain whether accent change affects individuals during their lifetimes or is only brought about by new generations of speakers accepting different pronunciations as the norm and effectively speaking with a different accent to older generations within their social circle. The variations/changes looked for were: CLOTH transfer, CURE lowering, GOAT allophony, R-sandhi, and T-voicing. The procedure of the study was to identify the presence or absence of these features in the speech of certain individuals in recordings made over a period of at least 35 years. The individuals studied were: Her Majesty Queen Elizabeth II, Baroness Thatcher, Sir David Attenborough and David Dimbleby. The results of these comparisons suggest that individual speakers are not greatly affected by changes in pronunciation taking place around them and generally stay with the preferred pronunciation of their youth. There are, however, cases where a general uncertainty amongst speakers of the accent, here found in CURE lowering, does influence the speech of individuals over time

MizAR 60 for Mizar 50

As a present to Mizar on its 50th anniversary, we develop an AI/TP system that automatically proves about 60% of the Mizar theorems in the hammer setting. We also automatically prove 75% of the Mizar theorems when the automated provers are helped by using only the premises used in the human-written Mizar proofs. We describe the methods and large-scale experiments leading to these results. This includes in particular the E and Vampire provers, their ENIGMA and Deepire learning modifications, a number of learning-based premise selection methods, and the incremental loop that interleaves growing a corpus of millions of ATP proofs with training increasingly strong AI/TP systems on them. We also present a selection of Mizar problems that were proved automatically