首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Strategies for poverty alleviation and sustainable natural resource management usually focus on land use options for improving yields. Increasing the returns to critical factors requires possibilities for input substitution. Inadequate timing of input applications or nonavailability of complementary factors can seriously hinder this substitution. Such constraints particularly apply in less‐favored areas where soil organic matter content is too low for enabling efficient nutrient uptake and soil structure limits water infiltration and moisture retention. This article focuses attention on the importance of labor for crop management activities and input applications that enhance input efficiency in highland area cropping systems of Northern Ethiopia. Given the inherent complementarities between labor and nutrient supply during critical phases of the plant growth process, input efficiency strongly depends on labor use. We present a semiparametric bioeconomic modeling approach to analyze the available options for improving input efficiency in agricultural production. Input response equations are used that consider the returns per unit of land and labor as a function of specific combinations of material inputs and management practices. Critical trade‐offs may arise when opportunity costs for labor are considered or when complementary factors appear as binding constraints. The model enables assessment of feasible pathways for enhancing sustainable intensification and poverty alleviation in typical settings of the East African highland region.  相似文献   

2.
Shifting cultivators manage soil not only by adjusting soil use on already‐cleared lands, as in continuous cultivation, but also by clearing forests to obtain new fertile soils. This study examines the crucial link between on‐farm soil conservation and deforestation in shifting cultivation by modeling forest clearing as an investment in soil for a private farmer. More generally, by doing so the study attempts to integrate deforestation and soil conservation models which have been separately developed in the literature. Our policy goal is to arrest tropical deforestation—as destruction of global commons—caused by land degradation in shifting cultivation while improving the well‐being of poor shifting cultivators. Our integrated approach enables joint policy analyses of deforestation and land degradation. Three welfare‐enhancing policies are considered. The first is agricultural and nonagricultural subsidies affecting farm and nonfarm income opportunities. The second is fiscal and tenure policies affecting discount rates. Our question is whether the link between forest clearing and soil fertility alters the outcomes of these two standard macroeconomic policies commonly found in the literature. The third policy (or program) is various soil conservation measures affecting soil regeneration and erosivity on already‐cleared lands. This article examines a very important question which has received little attention in previous theoretical works: can soil conservation reduce deforestation? This study confirms anti‐deforestation effects of the promotion of nonfarming activities—a common and often emphasized finding in previous works—among shifting cultivators. More importantly, it also demonstrates that improving various soil conservation measures not only discourages forest clearing among shifting cultivators but also tends to have greater effects on forest protection than promoting nonfarming activities. Contrarily, agricultural price subsidy or technological progress gives rise to the opposite outcome, and lowering the farmer's discount rate or improving tenure security encourages him/her to clear more forests just to accumulate soil.  相似文献   

3.
The Lore Lindu region in Indonesia—as in many forest frontier areas in Southeast Asia—has experienced rapid deforestation due to agricultural expansion in the uplands, at the forest margins. This has resulted in aggravated problems of erosion and water availability, threatening agricultural productivity growth. At the same time, technical progress is promoting agricultural intensification in the lowlands. In this article, we examine how improved technologies for paddy rice cultivation in the lowlands have affected agricultural expansion and deforestation in the uplands. The question of a “forest‐saving” or “forest‐clearing” effect related to technical innovation is important from a sustainable development perspective and remains a controversial issue in the literature. We address this question for the Lore Lindu region with an empirical model in which expansion in the lowlands and the uplands is estimated simultaneously. We use data from an extensive village survey conducted in the region, combined with GIS data. To guide the empirical analysis, we develop a theoretical framework based on a Chayanov‐type agricultural household model. The model analyzes farmers' land allocation decisions, taking into account the lowland–upland dichotomy in the agricultural sector. The empirical findings, corroborated by the analytically derived results, show how technical progress for lowland production affects land use at the forest margins and how these effects depend on the factor‐intensity of the technology. The findings imply specific rural development policies for sustainable agricultural intensification in forest frontier areas.  相似文献   

4.
5.
6.
7.
Is a reduced share of agriculture in the economy an obstacle for the agricultural sector to play an important role in poverty alleviation? What is the key channel, if any, by which agriculture is benefiting the poor in Chile that would be worthwhile to promote in other countries? By answering these questions we expand the literature on poverty and composition of growth by proposing a methodology that allows to disentangle the mechanisms by which agricultural growth can be poverty reducing. We find that in Chile agriculture plays a large role in reducing poverty, and most of this effect is channeled through the labor market.  相似文献   

8.
Promotion of adherence to healthy-eating norms has become an important element of nutrition policy in the United States and other developed countries. We assess the potential consumption impacts of adherence to a set of recommended dietary norms in the United States using a mathematical programming approach. We find that adherence to recommended dietary norms would involve significant changes in diets, with large reductions in the consumption of fats and oils along with large increases in the consumption of fruits, vegetables, and cereals. Compliance with norms recommended by the World Health Organization for energy derived from sugar would involve sharp reductions in sugar intakes. We also analyze how dietary adjustments required vary across demographic groups. Most socio-demographic characteristics appear to have relatively little influence on the pattern of adjustment required to comply with norms. Income levels have little effect on required dietary adjustments. Education is the only characteristic to have a significant influence on the magnitude of adjustments required. The least educated rather than the poorest have to bear the highest burden of adjustment. Our analysis suggests that fiscal measures like nutrient-based taxes may not be as regressive as commonly believed. Dissemination of healthy-eating norms to the less educated will be a key challenge for nutrition policy.  相似文献   

9.
Although the long-term economic impacts of the AIDS epidemic on orphans have been major concerns, few studies have investigated the impacts of orphan status into adulthood. Therefore, this article examines the education attainment and land inheritance of former orphans, who have lost at least one parent before reaching the age of 15 years, by using household surveys in Kenya. We find about a one-year lower educational attainment among former maternal orphans compared with former nonorphans among adults who started schooling before the Free Primary Education program introduced in 1974 but not among adults who started schooling after 1974. On inherited land, we find no significant difference between households headed by former orphans and nonorphans, after controlling for land owned by parents, numbers of brothers and sisters, and birth order among brothers.  相似文献   

10.
Shifting cultivation and forest pressure in Cameroon   总被引:1,自引:0,他引:1  
Shifting cultivation is often blamed as a principal cause of deforestation in tropical Africa. It is claimed that the practice is unsustainable because shortened fallow lengths result in soils too degraded to support forest vegetation. The decline in fallow lengths is often attributed to increases in population density and greater market participation. The conventional wisdom makes several claims that are as yet unsubstantiated. This article investigates whether there is evidence to support two of these claims in southern Cameroon. First, using both cross‐sectional and panel data, I find that there is indeed a robust negative association between fallow lengths and population density in the study area and weaker evidence for a negative relationship between fallow lengths and market participation. Second, a stochastic frontier production function approach is used to investigate the marginal contribution of fallow to output. Results indicate that fallow lengths are not low enough to be affecting yields and therefore do not appear to be resulting in declines in soil fertility. Thus overall, while some of the assumptions of the conventional wisdom appear to be true, there is little evidence to support its dramatic conclusion that shifting cultivators are causing deforestation in the forested region of Cameroon.  相似文献   

11.
Studies on input adoption consider education as one of the most important factors that affect adoption decisions. However, very little is known about the spill‐over effect of intra‐household education on the adoption process and about the impact of education on adoption decisions under different socioeconomic conditions. We investigate these two issues using a discrete choice model. The results indicate that the decision making process is a decentralised one in which educated adult members of the household actively participate in the decision making process. This casts doubt on the traditional assumption that the household head is the sole decision maker. The results reveal that there is a substantial and statistically significant intra‐household spill‐over effect of education on the adoption decision of households. The results of the study also show that the coefficient of the education and the environment interaction variable is negative and statistically significant. This demonstrates that education and socioeconomic environments could be substitutes in modern environments and complementary in traditional ones. This implies that the expansion of education in traditional areas may be more attractive than in modern areas since education is usually the only means to enhance the ability of farmers to acquire, synthesise and respond to innovations such as chemical fertiliser.  相似文献   

12.
The paper investigates the linkages between technological change and production risk, with an application to corn. The effects of technology on risk exposure are analyzed. We define technological progress to be risk‐increasing (risk‐decreasing) if it increases (decreases) the relative risk premium. The analysis is applied to panel data from Wisconsin research stations. Conditional moments (including mean, variance and skewness) of corn yield, grain moisture and corn profit are estimated for different sites. We investigate how the trade‐off between expected return and the risk premium varies over time and over space. The empirical results indicate that technological progress contributes to reducing the exposure to risk as well as downside risk in corn production, although this effect varies across sites. They also stress the role of the relative maturity of corn hybrids as a means of managing risk.  相似文献   

13.
This study employs the propensity score matching model to examine the impact of the adoption of water conservation and intensification technologies on farm output and income among small-scale lowland rice farmers in the Northern Region of Ghana. The matching was conducted based on the Mahalanobis distance combined with the propensity score. Balancing tests by checking the mean standardized absolute bias in the matched sample were conducted as well as a sensitivity analysis was conducted to check for hidden bias due to unobservable selection. The empirical results show a positive and significant impact of the adoption of bunds technology on input demand as well as a positive but insignificant impact on output supply and net returns. Adopters of the dibbling technology were found to have higher output supply, whereas no statistically significant difference was found between the incomes of adopters and nonadopters of dibbling seed method. The results, however, reveal a positive and significant effect on output and net returns when the dibbling method is combined with intensified weeding. The estimates were found to be relatively insensitive to hidden bias.  相似文献   

14.
In this study, we evaluate the preference of consumers in Niger for different tuwo or couscous characteristics using a random utility‐based choice experiment, ordered probit analysis, and tree‐based partitioning. Data were collected through a structured survey administered at four sites. Preferences are estimated for three products (couscous, fermented tuwo, and nonfermented tuwo) made from five pearl millet cutivars. We provide relative valuation for different traits by type of product. Results show that product taste, color, and textural attributes are important, especially for tuwo and couscous. Probit and partitioning results show that taste and color are the first attributes that consumers use to distinguish more preferred millet food products from less preferred millet food products. This should provide some direction for millet breeding programs and food processing of millet.  相似文献   

15.
The growing body of literature devoted to studying the impact of inequality on economic growth has centered its attention on the income distribution effect, even though the theoretical relationships are more related to assets distribution. While some recent studies have tried to overcome this limitation by introducing asset indicators, they meet new constraints when dealing only with time-invariant measurements for this explanatory variable. This article provides a theoretical discussion and some novel empirical tests to better understand the relationships between assets distribution and economic growth. We assembled a new panel database that includes observations for more than 30 countries over the last three decades. The data include a time-varying variable for changes in the Land Gini index over this period that enables us to overcome the limitations of previous studies. A system general method of moments (GMM) estimator is used to generate truly unbiased and consistent estimates for the parameters of interest. We explore some of the likely channels through which asset distribution and economic growth may be linked, paying particular attention to the role of secure property rights and the relations between land ownership and education. We find robust and significant negative signs for land inequality in the growth regressions, indicating that changes in asset distribution are an important factor for economic development.  相似文献   

16.
An assessment of the current structure of food demand in urban China   总被引:3,自引:0,他引:3  
We evaluate the current structure of food demand in urban China by using household expenditure survey data from five provinces. Two complementary analyses are undertaken. First, an aggregate analysis based on a fractional logit model is used to examine how households allocate food expenditures across the food‐at‐home (FAH) and food‐away‐from‐home (FAFH) categories. This is followed by a disaggregated analysis of how households allocated their FAH expenditures across 12 commodity categories. A Quadratic Almost Ideal Demand System (QUAIDS) is used. We find evidence of significant food purchase substitution and complementarity.  相似文献   

17.
This article examines economic efficiency (EE) of crop production of Russian corporate farms for 1993–1998. EE declined over the period, due to declines in both technical and allocative efficiency. Technical efficiency (TE) results indicate that output levels could have been maintained while reducing overall input use by an average of 29–31% in 1998, depending on the method used, while the allocative efficiency (AE) results show that costs could have been reduced about 30%. The EE scores show that Russian corporate farms could have increased efficiency by reducing the use of all inputs, particularly fertilizer and fuel. Russian agriculture inherited machinery‐intensive technology from the Soviet era, which may be inappropriate given the relative abundance of labor in the post‐reform environment. Investment constraints have prevented the replacement of old machinery‐intensive technology with smaller scale machines that allow for a more labor‐using technology.  相似文献   

18.
We tested a theoretical model with the Marshallian inefficiency (H1) and threat of eviction (H2) hypotheses having opposite effects on land productivity on sharecropped plots. The model also assumes that kinship contracts may eliminate or reduce the Marshallian inefficiency (H3) and threat of eviction (H4) effects on land productivity. Our empirical findings were consistent with H2 and H4 being true. We found higher land productivity on sharecropped plots than on share tenants' own plots and higher land productivity on sharecropped plots of nonkin than of kin tenants. The nature of the data allowed controlling for unobservable household characteristics through household fixed effects and for observable plot characteristics. Analyses with and without plot characteristics revealed that these findings were stronger with plot characteristics than without them. Based on the plausible assumption that observable plot characteristics are positively correlated with unobservable plot characteristics this strengthens our conclusion. The results are also supported by first-order stochastic dominance analysis. Sharecropped plots' output value distribution unambiguously dominated the output value distribution from share tenants' own plots. Nonkin sharecropped plots' output value distribution also first-order stochastically dominated the output value distribution from kin sharecrop plots.  相似文献   

19.
This article investigates the effects of wheat genetic diversity and land degradation on risk and agricultural productivity in less favored production environments of a developing agricultural economy. Drawing production data from a household survey conducted in the highlands of Ethiopia, we estimate a stochastic production function to evaluate the effects of variety richness, land degradation, and their interaction on the mean and the variance of wheat yield. Ethiopia is a center of diversity for durum wheat and farmers manage complex variety mixtures on multiple plots. Econometric evidence shows that variety richness increases farm productivity. Variety richness also reduces yield variability but only for high levels of genetic diversity. Simulations with estimated parameters illustrate how planting more diverse durum wheat varieties on multiple plots contribute to improving farmer's welfare.  相似文献   

20.
This paper tests for the influence of advertising on the inter‐product distribution of consumer demand for non‐durable goods and services in the UK, 1963–1996. The long‐run demand for seven categories of non‐durable products is modelled through an advertising‐augmented version of the almost ideal demand system (AIDS), which is incorporated into an error‐correction model to allow for short‐run dynamic adjustments to long‐run equilibrium positions. Model estimates confirm that the restrictions of price homogeneity and symmetry appear to be consistent with the data, yield measures of the various types of demand elasticity that are in general plausible, confirm the strong influence of prices on the allocation of consumer expenditure, but find little evidence to support the hypothesis that advertising has the power to effect marked changes in the inter‐product pattern of consumer demand in the UK.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号