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1.
Irrigation water productivity in Cambodian rice systems   总被引:1,自引:0,他引:1  
Knowledge of the marginal productivity of water is crucial for decisions about its allocation between uses, which is particularly important in the context of increasing competition for water. Using primary, plot‐level panel data, this article estimates the marginal productivity of water from supplementary irrigation in lowland rice systems in Cambodia, taking into account farmer and plot heterogeneity as well as self‐selection of supplementary irrigation. Our estimates indicate a range of elasticities for rice output with respect to water inputs of between 0.057 and 0.069 for wet season production, substantially lower than previous estimates based on either aggregate or trial data. We discuss the policy implications of these results, in particular with respect to the utility of demand management policies and the challenges they pose to the decentralization of water management to Farmer Water Users Groups.  相似文献   

2.
The most obvious reason for studying labour productivity is that it can reasonably be regarded as one of the dimensions of market performance: firms which exhibit a high rate of increase of labour productivity are, other things being equal, “better” than firms with a low rate of increase. Similarly, concentration, a dimension of market structure, can be regarded as having normative implications. Although the selection of these variables as being worthwhile ones for study clearly rests on their value as normative indicators, the scope of this paper is essentially positive in content. Its purposes are: first, to provide estimates of changes in labour productivity and of changes in concentration in the food processing industries in the decade 1954-63; second, to attempt to test various hypotheses concerning the causes of different rates of change of productivity (including the hypothesis that increasing concentration has helped to raise productivity); and in conclusion to consider some of the possible effects of productivity changes.  相似文献   

3.
This study estimates the distributional heterogeneity in the effects of climate change on yields of three major cereal crops: rice, maize, and wheat in India using district-level information for the period 1966–2015. We distinguish between the effects of changes in growing season weather from those due to changes in long-term climate trends and the heterogeneity in these effects across the distribution of crop yields by estimating naïve and climate penalty inclusive models using fixed-effect quantile panel models. We observe an absence of adaptation against rising temperatures for rice and wheat. However, we find a statistically significant presence of adaptation for wheat and maize for changes in precipitation, though the magnitude is small. Moreover, we find that the effects are asymmetric, and are larger at the lower tail of productivity distribution and smaller at the upper tail of the distribution. A 1°C increase in temperature lowers rice and wheat productivity by 23% and 9%, respectively at the first quantile, but the damage is only 6% and 5% at the ninth quantile. Heterogeneity in impacts and adaptation estimates over the yield distribution curve and across crops suggests the importance of customizing strategies for adaptation to changing weather and climate conditions across regions, crops, and current productivity levels.  相似文献   

4.
Imported goods play a central role in determining the gains from trade. Using detailed trade and firm‐level data for Italy and France, we investigate the relationship between trade integration, imported intermediate inputs and firm performance in the food industry. Our main findings show that an increase in import competition spurs firm‐level productivity growth. Furthermore, the productivity growth effect attributable to imported intermediate inputs is significantly stronger than the effect due to imported final products. In addition, we find that new imported inputs are of particular importance, especially for Italian food firms, though less so for the French firms. Finally, the productivity growth effect of trade integration tends to be asymmetric across firms: more productive firms gain more from trade integration. These stylised facts have interesting policy implications.  相似文献   

5.
This article presents estimates of the recreational value of fishing in New Zealand. The data was obtained from a large-scale interview conducted at boat ramps across New Zealand. The results suggest that the recreational value of a species depends critically on the motives for targeting a particular species. Species targeted for eating purposes have marginal values that appear to closely reflect the market price of the fish (i.e. the opportunity cost). In contrast, those species which are sought mainly for recreational purposes, have a higher value. Furthermore, values for these fish types were found to be greatest for scarce species and large species of fish. The article examines the robustness of the estimates to determine whether strategic bias, embedding effects or hypothetical bias influence the results.  相似文献   

6.
This paper develops a short-run microeconomic simulation model of the Dutch glasshouse industry in order to investigate the relation between technical efficiency and marginal abatement costs of CO2 emission. The model is also used to determine the effects of an emission tax and systems of tradable and non-tradable quota for groups of firms with different rates of technical efficiency. The results show that marginal abatement costs are very responsive to changes in technical efficiency. Furthermore, it is found that firms with a low technical efficiency are faced with a higher profit reduction under different abatement policies than firms with a high technical efficiency.  相似文献   

7.
农户经营规模和土地生产率关系是发展经济学领域的经典议题之一。本文在土地流转加速发展的背景下讨论了我国农户经营规模扩大对土地生产率的影响以及测量两者之间关系面临的种种干扰。除了农户规模本身的作用外,理论和实证检验均表明存在土地流转市场时不同规模农户在土地生产率上的差异还可能源于农户和土地的异质性,譬如土地更多流向经营能力强的农户、流转多劣地等等。基于固定农户的固定地块数据可以有效控制异质性的实证策略,本文利用4个省两期跟踪调查数据对两者关系进行了再检验。研究发现,来自固定农户固定地块的证据表明农户土地经营规模扩大并不会影响粮食单产,而不控制固定地块时往往会得到两者负相关的伪结论,并且仅控制固定农户时上述伪结论更为明显。这一结果意味着不必担心规模经营会威胁粮食供给。  相似文献   

8.
This paper studies the effects of investment support from the common agricultural policy on labour and total factor productivity of agricultural firms in Sweden. Detailed firm-level data on 34 300 firms are used to estimate a matched panel model that relates firm productivity to a series of factors reflecting internal and external characteristics. The recently developed Coarsened Exact Matching method is used to estimate matched control groups and handle selection bias. Findings show a positive and significant treatment effect of investment support on firm productivity, but only for small firms. The analysis also reveals that an increase in the size of the support in relation to firm income has a negative and significant impact on productivity for all firms. Differentiating between various types of investment supports indicates heterogeneous treatment effects. The policy instrument can improve its efficiency if targeted to small firms and investments that have a link to public good provision.  相似文献   

9.
In parametric efficiency studies, two alternative approaches exist to provide an estimate of the long‐run efficiency of firms: the dynamic stochastic frontier model and the generalised true random‐effects model. We extend the former in order to allow for heterogeneity in the long‐run technical efficiency of firms. This model is based on potential differences in firm‐specific characteristics and in firms’ inefficiency persistence. The model is applied to an unbalanced micro‐panel of German dairy farms over the period 1999 to 2009. Estimation of long‐run technical efficiency and inefficiency persistence is based on an output distance function representation of the production technology and estimated in a Bayesian framework. The results suggest that heterogeneity in long‐run technical efficiency of farms is mostly attributed to discrepancies in farm‐specific factors rather than differences in farms’ inefficiency persistence. Farm size is positively related to long‐run technical efficiency while subsidies exert a negative effect on the long‐run technical efficiency of farms. Inefficiency persistence is found to be very high, but heterogeneity in this persistence is low.  相似文献   

10.
The reduction of adverse health and environmental effects from pesticide use is currently a top priority on the agricultural policy agenda. Efficient pesticide policies must take into account farmers’ application behavior, especially effects of pesticide use on economic risk. However, previous results regarding the direction of risk effects of pesticides are ambiguous. We show that the ambiguity in earlier studies could be due to the pesticide indicator selected. Indicators which fail to account for the heterogeneous properties of pesticides may be inapt for interpreting farmers’ pesticide use decisions. Our analysis, based on a rich panel dataset of Swiss wheat producers with highly detailed information on pesticide use, considers different pesticide indicators and multiple sources of uncertainty. Our key finding is that indicator choice affects the magnitude and sign of estimated risk effects. Estimates of pesticide productivity and risk effects are significantly higher for fungicides, and even reversed for herbicides when we measure pesticide use in simple quantity units (kilogram per hectare) - compared to the quality and intensity corrected Load Index. This means for example, that farmers will ceteris paribus use lower quantities of herbicides, but will increase the overall toxicity of the products applied with increasing risk aversion. We discuss implications of our findings for the design of pesticide policies and agricultural risk management instruments.  相似文献   

11.
This article explores the potential and limitations for using farmyard manure (FYM) to improve paddy and upland cereals productivity under various soil conditions in Tamil Nadu, India. Using household‐level fixed effects, estimated yield functions from 1993 to 2003 confirm that FYM application directly increases crop productivity in upland cereals, but not in paddy rice. Complementary effects through an increase in the marginal product of inorganic fertilizer is observed for both paddy and upland cereals, especially where inherent soil fertility is low. Farmers’ FYM use is responsive to changes in the price of FYM, but transport costs limit price transmission across space. Dairy sector development thus improves crop productivity, but only in the small area around the animals which limits the spread of FYM‐based development strategy.  相似文献   

12.
Models used for policy evaluation rarely consider firm heterogeneity, despite its importance for instrument design. This study considers agent heterogeneity explicitly in the evaluation of policies for nonpoint pollution control through the integration of decomposition and calibration procedures for programming models. The application concerns the regulation of nitrate leaching from intensive dairy production in the Waikato region of New Zealand. Failing to represent firm heterogeneity leads to widely different estimates of mitigation costs, relative to where heterogeneity is considered. Variation in baseline emissions and the slopes of abatement cost curves between firms renders a differentiated policy less costly than a uniform standard. However, the relative values of these policies are not broadly different, as firms required to do the most abatement – intensive farms with large baseline pollutant loads – can do so more cheaply, on average.  相似文献   

13.
This article uses an equilibrium displacement model (EDM) to assess the impact of a change in trade policy in the Korean infant formula market that is assumed to be oligopolistic. Domestic oligopolists compete in a market for a homogenous good with importing firms who enjoy the same level of market power as the domestic producers. Within an EDM framework, we investigate how the market adjusts to a new equilibrium in response to an external policy shock that improves access to foreign goods. Our empirical work consists of two steps. We first econometrically estimate the market demand elasticity and market power parameter. Then, using these estimates, we simulate our EDM model to assess the distributional effects of tariff cuts and other changes in marginal cost. Simulation results show that, with a lower market price and increased consumption, the change in consumer surplus resulting from tariff reduction is unambiguously positive, but that the change in social welfare can be in either direction, depending on who receives market rents associated with imports. When importing firms are domestic, the domestic welfare change is definitely positive. However, in the case of foreign importing firms, the direction of the welfare change crucially depends on the demand elasticity.  相似文献   

14.
This paper analyzes aggregation over firms assuming mean scaling, i.e., the relative distribution of micro variables is independent of the distribution of the aggregates. We emphasize cost-minimization models encompassing general functional forms and heterogeneity of outputs and technology across firms. Mean scaling implies that aggregate relations inherit properties of micro behavior. The mean scaling hypothesis is not rejected using annual time-series data on wheat production for crop districts in Manitoba.  相似文献   

15.
Canada's average cost for milk production is among the highest in the world. This paper focuses on specific potential causes by estimating economies of scale and technical efficiency for a panel of Quebec dairy farms that spans the 2001–10 period. Additionally, this paper investigates the sources of total factor productivity growth. The stochastic frontier analysis, based on an input‐distance function, is used to estimate returns to scale relationships across dairy farms. The results show that there is significant economies scale to be exploited and that cost of production could also be reduced by improving technical efficiency. Accordingly, the paper indicates that input‐mix effect is the main source of total factor productivity growth. The results have important implications for Canada's supply management policy, and more specifically for the trading of production quota between dairy farmers, as well as for the delivery of targeted extension services.  相似文献   

16.
Structural heterogeneity (SH)—i.e. the existence of marked asymmetries in labour productivity among firms, along with low-productivity firms forming a large share of total employment—plays an important role in development theory. But only recently has the availability of micro data made the rigorous measuring of SH possible. This paper makes compatible different databases on manufacturing production, innovation and micro-social data for Brazil—PIA, RAIS, Secex and PINTEC—for 2000–2008 in order to measure SH and analyse its determinants. First, productivity groups are formed out of the universe of Brazilian manufacturing firms using a k-mean cluster methodology. Second, the variables affecting the productivity group to which each firm belongs are tested using an ordered probit model. The results indicate that increasing returns (captured by the firm's market share, the number of employees in innovative activities, workers' years of schooling and the accumulation of workers' experience), the technological intensity of the industry, learning by exporting and public support to R&D have driven productivity growth and reproduced SH through time, as predicted by development and evolutionary theories.  相似文献   

17.
This paper estimates technical efficiency (TE) measures using four alternative production frontier models, and evaluates the sensitivity of the results to the choice of methodology. The Cobb-Douglas functional form along with data for 1982 and 1983 from 404 dairy farms located throughout six northeastern states in the US are used in the estimation. A general conclusion is that, broadly speaking, frontier function models are neutrally upwardly scaled versions of the OLS or average model. A second conclusion is that different models yield markedly different efficiency levels across firms. However, the correlation between the indexes from the various methods is high, which implies that the ordinal ranking of firms according to their measured level of technical efficiency appears to be independent of the method used for a given year. By comparison, the correlation between efficiency indexes for the same method across time, although positive, is much lower than the previous set of correlations. Correlation analysis of efficiency versus farm size and of efficiency versus returns over variable costs, based on the alternative models, yielded consistent results.  相似文献   

18.
In this paper we present results from two choice experiments (CE), designed to take account of the different negative externalities associated with pesticide use in agricultural production. For cereal production, the most probable impact of pesticide use is a reduction in environmental quality. For fruit and vegetable production, the negative externality is on consumer health. Using latent class models we find evidence of the presence of preference heterogeneity in addition to reasonably high willingness to pay (WTP) estimates for a reduction in the use of pesticides for both environmental quality and consumer health. To place our WTP estimates in a policy context we convert them into an equivalent pesticide tax by type of externality. Our tax estimates suggest that pesticide taxes based on the primary externality resulting from a particular mode of agricultural production are a credible policy option that warrants further consideration.  相似文献   

19.
It is notoriously difficult to assess the economic value of research aimed at improving research capacity, particularly for the human capital component of research capacity. In this paper, a framework is developed and an analysis is undertaken of the value of training for scientists in wheat rust resistance. The value of improving human capital is assessed through a framework based on marginal analysis of the improvement in productivity outcomes flowing from the increased capacity. On that basis, the value of programs to build human capacity through training or further education can be estimated. Although such estimates are necessarily qualified, they provide a basis for quantifying the value of building research and development capacity.  相似文献   

20.
Sustainable agricultural intensification (SAI) practices have been promoted in developing countries to improve farm productivity and environmental services. However, it is still unclear whether use of a combination of SAI practices has a significant influence on the cost efficiency of smallholder farms. This study investigates whether the cost efficiency of smallholder maize producers in Ethiopia depends on use of input-augmenting and agronomic SAI practices. Stochastic cost frontier models that account for heterogeneity across farms are used for estimation. We find that the use of individual SAI practices increases cost while the combined use of the practices reduces it. The marginal effect on cost reduction is substantial when SAI practices are set at their sample maximum levels. Overall, the results demonstrate the benefit of using a combination of SAI practices in minimizing production cost while addressing the adverse effects of soil degradation and climate variability. To enhance food security, smallholder farm incomes and the sustainability of production in developing countries, policy programs should focus on promoting packages of input-augmenting and agronomic SAI practices.  相似文献   

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