Leah K. Vanwey

• PhD
• Professor at Brown University

Previous research has consistently found a negative statistical relationship between sibship size and children's intellectual development. Two explanations have been offered for this finding. The prevailing explanation is that the relationship is causal, suggesting that limiting family size would lead to more intelligent children. A second explanat...

Between 2003 and 2013, sugarcane area expanded six-fold, from 142,000 ha to 847,000 ha, in Goiás State and the Federal District, Brazil. And while there has been much research on land-use dynamics of sugarcane expansion in established sugarcane growing regions, little is known about the dynamics associated with its expansion in sugarcane frontiers...

Our recent article, “Are Brazil’s Deforesters Avoiding Detection?” demonstrated that focusing illegal deforestation enforcement on the subset of forest monitored by the flagship PRODES system has caused PRODES to capture a declining share of deforestation in the Brazilian Amazon. Deforesters may be purposively seeking out forests not monitored for...

Rates of deforestation reported by Brazil's official deforestation monitoring system have declined dramatically in the Brazilian Amazon in recent years. Much of Brazil's success in its fight against the clearing of monitored forests stems from a series of policy changes put into place between 2004 and 2008. In this research we suggest that one of t...

Agricultural intensification in the tropics is one way to meet rising global food demand in coming decades[1,2]. Although this strategy can potentially spare land from conversion to agriculture[3], it relies on large material inputs. Here we quantify one such material cost, the phosphorus fertilizer required to intensify global crop production atop...

The sensitivity of agricultural output to climate change has often been estimated by modelling crop yields under climate change scenarios or with statistical analysis of the impacts of year-to-year climatic variability on crop yields. However, the area of cropland and the number of crops harvested per growing season (cropping frequency) both also a...

An analysis of data on property size and type as well as land use reveals the distribution of deforestation, remaining forest cover and carbon stocks in Mato Grosso, Brazilâ €™ s third largest state. Nearly two-thirds of remaining forests and carbon reserves, equating to between 2 and 3 Pg of carbon, are located on private properties. Around 80% of...

Developing the Amazon into a major provider of internationally traded mineral and food commodities has dramatically transformed broad expanses of tropical forests to farm and pasturelands and to mining sites. The environmental impacts of this transformation, as well as the drivers underlying the process, have already been well documented. In this a...

In this research we consider rural out-migration from two study sites in western Pará in the Amazon Basin. Here we argue that out-migration is strongly influenced by historical context, and by the legacy institutions associated with each site’s period of colonization. We support our argument with longitudinal survey data collected from the rural su...

In this research we consider the impact of export-driven, soybean agriculture in Mato Grosso on regional economic growth. Here we argue that the soybean sector has served as a motor to the state's economy by increasing the demand for services, housing, and goods, and by providing a source of investment capital to the non-agricultural sector. Specif...

As urbanization rates rise globally, it becomes increasingly important to understand the factors associated with urban out-migration. In this paper, we examine the drivers of urban out-migration among young adults in two medium-sized cities in the Brazilian Amazon—Altamira and Santarém—focusing on the roles of social capital, human capital, and soc...

This letter uses satellite remote sensing to examine patterns of cropland expansion, cropland abandonment, and changing cropping frequency in Mato Grosso, Brazil from 2001 to 2011. During this period, Mato Grosso emerged as a globally important center of agricultural production. In 2001, 3.3 million hectares of mechanized agriculture were cultivate...

Garrett et al’s recent letter (2013 Environ. Res. Lett. 8 044055) shows the trade value of Brazil’s production of non-genetically modified (GM) crops, and argues that production for this niche market laid the foundation for the expansion of a variety of non-GM and eco-certification systems. We argue that the conditions underlying the development an...

Rural settlement in previously sparsely occupied areas of the Brazilian Amazon has been associated with high levels of forest loss and unclear long-term social outcomes. We focus here on the micro-level processes in one settlement area to answer the question of how settler and farm endowments affect household poverty. We analyze the extent to which...

This paper analyses the contribution of the biophysical characteristics, accessibility conditions and land use/cover classes on poverty dynamics among rural smallholders in Altamira, State of Pará. Poverty-environment literature points that the increasing institutional restrictions to deforestation, along with lack of titling, may affect the abilit...

The Brazilian agro-industrial frontier in Mato Grosso rapidly expanded in total area of mechanized production and in total value of production in the last decade. This article shows the spatial pattern of that expansion from 2000 to 2010, based on novel analyses of satellite imagery. It then explores quantitatively and qualitatively the antecedents...

This article analyzes off-farm work among subsistence-level farmers in the Santarém region of the Brazilian Amazon. We build on the literature on rural livelihoods in the Global South by exploring how the opportunity to work off the farm is embedded in social relationships. We additionally differentiate our analysis by type of off-farm work, and ex...

Building upon previous modelling efforts, an agent-based model of land use change has been developed to model small-scale agriculture in the Brazilian Amazon. The model, LUCITA (Land Use Change in the Amazon), simulates heterogeneous farming household agents during the period of 1970–2000, settling and developing properties west of Altamira, Pará,...

One of Daniel Hogan's lasting impacts on international demography community comes through his advocacy for studying bidirectional relationships between environment and demography, particularly migration. We build on his holistic approach to mobility and examine dynamic changes in land use and migration among small farm families in Altamira, Pará, B...

Recent research on the human-environment interactions influencing land use change in parts of the Brazilian Amazon has focused on the importance of the household as an agent of change. In areas of the rainforest that are characterized by household-based agricultural colonization, such as the area near Altamira, research has begun to reveal how patt...

The objective of this article is to present Polarization of Agrarian Structure as a single, more complete representation than models emphasizing rural exodus and consolidation of land into large agropastoral enterprises of the dynamics of changing land distribution, land use / cover, and thus the rural milieu of Amazonia. Data were collected in 200...

The objective of this article is to present Polarization of Agrarian Structure as a single, more complete representation than models emphasizing rural exodus and consolidation of land into large agropastoral enterprises of the dynamics of changing land distribution, land use / cover, and thus the rural milieu of Amazonia. Data were collected in 200...

What motivates family members to share resources? Past research argues for, on the one hand, love and altruism, and on the other, the expectation of reciprocity. Drawing on this literature, this paper examines intergenerational transfers between small farmers and their non-coresident children in the rural area around the city of Altamira, Pará, Bra...

What motivates family members to share resources? Past research argues for, on the one hand, love and altruism, and on the other, the expectation of reciprocity. Drawing on this literature, this paper examines intergenerational transfers between small farmers and their non-coresident children in the rural area around the city of Altamira, Pará, Bra...

Cross-site comparisons of case studies have been identified as an important priority by the land-use science community. From an empirical perspective, such comparisons potentially allow generalizations that may contribute to production of global-scale land-use and land-cover change projections. From a theoretical perspective, such comparisons can i...

This paper reviews and synthesizes findings from scholarly work on linkages among rural household demographics, livelihoods and the environment. Using the livelihood approach as an organizing framework, we examine evidence on the multiple pathways linking environmental variables and the following demographic variables: fertility, migration, morbidi...

This article describes a method to collect data on the spatial organization of land use within a rural property as part of a large-scale project examining the linkages between household demographic change and land use and land cover change in the Brazilian Amazon. Previous studies used several different spatial approaches, including maps and satell...

The papers in this special issue, resulting from two workshops intended to chart the way forward for studies of complex land-use dynamics, suggest that the paradigm of ‘complexity’, in its multiple meanings, raises both new opportunities and new challenges that require multidisciplinary attention. The opportunities include the potential to explore...

This article examines intergenerational coresidence among rural farm families near Santarém, Pará, Brazil using survey data collected by the authors on 896 children whose parents live in 175 households on 150 farms. Married adult children, daughters, and the best educated are more likely to live off their parents’ rural property (vs. on the propert...

Este artigo apresenta a estratégia usada em uma pesquisa realizada em Santarém – PA, em 2003, para amostrar lotes delimitados em mapas do Incra e as unidades domésticas ali existentes, de modo a capturar as mudanças populacionais e ambientais na escala das propriedades rurais e na da região. A amostra foi selecionada conforme a distribuição dos lot...

This article describes the strategy used in a study carried out in Santarém, State of Pará, Brazil, in 2003, to sample plots represented on maps produced by the Brazilian Government's Land Reform Department (INCRA). The purpose of this sampling strategy is to describe demographic and environmental changes on the scale of the rural landholdings and...

Demographic interest in population and environment has grown in recent decades. One of the most prominent research areas in this tradition addresses the impact of population on land use and land cover change. Building on this tradition, we examine the effects of household demographic composition on land use and land cover on small farms in two stud...

Estudos de População e Ambiente na Amazônia Brasileira têm buscado relacionar surveys sociodemográficos com dados de imagens de satélites para o entendimento do papel da demografia humana na mudança da cobertura da terra. No entanto, em ambas as fontes de dados (surveys e imagens de satélite), a escolha da escala afeta os resultados das análises, s...

This paper considers the size of a farmer’s property as a key variable influencing land cover and land cover change in rural areas of developing countries. Data from 126 rural familial properties in the region around the city of Santarém, Pará, in the Brazilian Amazon, indicate that property size is important for understanding the trajectories of l...

Recent theoretical, methodological, and technological advances in the spatial sciences create an opportunity for social scientists to address questions about the reciprocal relationship between context (spatial organization, environment, etc.) and individual behavior. This emerging research community has yet to adequately address the new threats to...

Throughout much of human history, changes to forest ecosystems have come about through natural climatic changes occurring over long periods of time. But scientists now find changes in forest cover dramatically accelerated by such human activities as large-scale agriculture, the building of dams and roads, and the growth of cities with vast areas of...

This study focuses on the effect of land ownership on internal and international out-migration in Mexico and on internal out-migration in Thailand. Land can impact migration in four ways: as wealth; as employment; as an investment opportunity; and through inequality in ownership. Discrete time event history models of individual migration, using dat...

This paper estimates village-level models of the effects of population variables on the area devoted to upland crop production in Nang Rong district, Thailand. The expansion of upland crops is part of the growth of market agriculture in Nang Rong, and a correlate of deforestation in this setting, The results show that population density (measured a...

Researchers studying migration and development have argued over the potential that migration and associated remittances have to improve the economic and social conditions in origin communities. Past research on migration from indigenous communities in Oaxaca has similarly questioned the compatibility of traditional governance systems with high migr...

Past research has questioned the extent to which remittances are altruistic behaviors versus payments in a contractual relationship between households and migrants. This article explores altruistic and contractual patterns of remittances using a gendered approach. On the basis of results with various levels of significance in regression models, mal...

In this study I consider land ownership as a determinant of temporary migration in a rural area of Thailand. Previous research on rural areas in developing countries has focused on the use of migration to diversify household incomes across economic sectors and across geographic areas. I combine this literature with economic theories of migration to...

Previous research has consistently found a negative statistical relationship between sibship size and children's intellectual development. Two explanations have been offered for this finding. The prevailing explanation is that the relationship is causal, suggesting that limiting family size would lead to more intelligent children. A second explanat...

A study of the College of Arts and Sciences at the University of North Carolina at Chapel Hill. Honors essay: Dept. of Sociology, University of North Carolina at Chapel Hill, 1996. Includes bibliographical references (leaf 19).