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21.
稻鳅共生种养模式试验研究   总被引:2,自引:0,他引:2  
[目的]稻鳅共生是典型的稻田综合利用模式,符合生态农业发展方向。通过对稻鳅共生生态系统的生理生态学机制开展试验研究,为进一步推广稻鳅共生种养模式提供科学依据。[方法]采用田间试验方法,以水稻单作为对照,研究了不同泥鳅养殖密度下的稻鳅共生对水稻农艺性状、土壤理化性质、水稻产量构成的影响,并对稻鳅共生种养模式进行了经济效益分析。[结果]与对照处理相比,水稻长势在株高、有效分蘖率、根长等方面有一定提高。养殖田水稻株高增高了3%,有效分蘖率提高了8%~11%,根长提高了8.8%~31.3%。在土壤理化性质方面,与对照相比,土壤容重降低了7.1%~21.2%,孔隙度增加了4.1%~14.7%。实验前后养殖田内土壤有机质增加了3.5%~26.5%,对照田降低了2.5%~5.8%。土壤肥力(氮、磷、钾)减少,但减少幅度小于对照处理。稻鳅共生种养模式下水稻产量提高了5%~25%,同时稻田增收泥鳅1 725~3 375kg/hm2,净收入为1.836 0万~2.307 0万元/hm2,经济效益提高了3.65~4.84倍。稻鳅共生种养模式中泥鳅的养殖密度为30万尾/hm2时稻田的生态效益和经济效益最佳。[结论]稻鳅共生有效改善了土壤理化性质,促进了水稻的生长,提高了稻田产量和产值。  相似文献   
22.
This study examines the sources of labor productivity growth dynamics in Japan (1970–2010) and investigates the extent to which Japanese economic performance has been affected by Baumol's growth disease (BGD). We find that BGD silently undermines Japanese economic growth. However, the magnitude is miniscule, and consequently the aggregate labor productivity growth rate has not been decreasing monotonically. We also explore how BGD is arising and why it is small in the Japanese economy. BGD is weak because (1) the positive Baumol growth effect is also working in certain services sectors and (2) BGD is not a durable phenomenon: even if a sector begins to suffer from BGD, it is likely to recover quickly.  相似文献   
23.
基于汇率传递的风险溢价渠道,本文将我国利率调控通胀、外汇储备对冲干预汇率纳入新凯恩斯政策模型,构建双目标双工具政策分析框架,比较泰勒规则与双目标双工具规则下通胀目标与汇率目标共存的经济机制与效应。本文模拟显示:(1)双目标双工具政策框架下通胀目标与汇率目标能够共存,此时通过影响汇率风险溢价来盯住汇率不影响通胀;而单工具政策下两目标无法共存,此时降低国内资产的收益率盯住汇率会刺激居民的消费行为引起通胀。(2)国际资本冲击下,双目标双工具政策在固定汇率的同时能保证经济稳定;而当贸易条件恶化时,选择完全浮动汇率制度最优。央行政策损失分析进一步验证了以上结论。(3)随着金融市场化改革深入,外汇储备稳定汇率的有效性将下降,冲销成本会大幅提升。资本账户开放下,双目标双工具政策仍是央行抵御外部资本冲击的首选政策;但是汇率市场化后,通胀目标制与双目标双工具政策效果基本无差异。本文结论的启示是:面对国际资本,需必要的汇率管制;但是面对贸易冲击,可适度提升汇率弹性来减少冲击对产出和通胀的影响。  相似文献   
24.
[目的]海南当前处于国际旅游岛建设和全面建成小康社会的关键时期,旅游业作为海南省的主导产业对海南经济发展的支撑作用显著增强,在此形势下,分析旅游业发展对海南经济增长的拉动效应,有利于为进一步提升旅游业对海南区域经济发展的影响,促进区域经济发展和经济结构转型,提出科学可行的对策和建议。[方法]文章从时间和空间两个维度,运用旅游业依存度、贡献率和拉动率3个指标,以旅游收入与地区生产总值等统计指标为基础,探讨了海南省旅游业对经济增长的拉动效应。[结果]从时间维度来看,海南省旅游业对地区经济增长的拉动作用进一步加大;从空间维度来看,海南省旅游业的拉动效应并不突出;从市(县)域维度来看,海南省各市(县)旅游业对经济增长拉动效应存在空间差异,东部地区拉动效应持续增长,中部地区增长势头迅猛,北部地区增长缓慢。[结论]不断完善海南旅游基础设施与管理体系;要不断细分和规范旅游产品,提升旅游产品的吸引力和复购率,完善营销及咨询服务体系;注意与其他产业的协调发展,加强与周边省份的交流与合作,省内要因地制宜,挖掘各地旅游业发展特色,推动各市(县)均衡发展,以进一步加强海南省旅游支柱产业的作用,并快速实现区域经济跨越式发展。  相似文献   
25.
Expectations are at the centre of modern macroeconomic theory and policymakers. In this article, we examine the predictive ability and the consistency properties of macroeconomic expectations using data of the European Central Bank (ECB) Survey of Professional Forecasters (SPF). In particular, we provide evidence on the properties of forecasts for three key macroeconomic variables: the inflation rate, the growth rate of real gross domestic product and the unemployment rate.  相似文献   
26.
研究目的:探究地方政府经济增长激励背景下,区域经济发展不平衡对土地违法行为的影响。研究方法:基于经济和社会科学领域有关发展不平衡及其影响效应的理论观点,结合中国特定的地方政府经济增长激励机制,以及土地利用与管理实际,探讨区域经济发展不平衡对土地违法行为的影响机理,并通过构建计量经济模型进行相应的实证检验。研究结果:区域内部经济发展差异的扩大确实会导致更多土地违法案件的产生和违法用地规模的增加;另外,在不同经济发展地区,区域内部经济发展差异变化对土地违法的具体影响有所不同。发达地区内部经济发展差异的扩大对土地违法的影响主要表现在违法面积上,而欠发达地区内部经济发展差异的扩大对土地违法的影响则主要表现在违法案件数上。研究结论:区域经济发展不平衡是导致土地违法行为的重要因素之一,促进和实现地区间的均衡发展有助于减少土地违法现象。  相似文献   
27.
Developing countries today have become more active participants in regional trade agreements. This raises questions about how the benefits of integration are distributed, and the extent to which lower‐income countries are able to capture development gains. Historically, such impacts have been difficult to identify with precision. This paper seeks to address this gap by empirically analysing the impact of regional integration on development, particularly the effects on growth and welfare. Using both bilateral and regional integration measures, we show that the ability to capture gains from integration varies across developing country regional groups, with developing Asia benefiting on par with developed countries. The findings in the paper indicate that trade and trade policy play an important role in reducing inequality and poverty in developing countries. It also shows that regionalism can function as a channel to make multilateralism a more adept way of addressing national challenges.  相似文献   
28.
Aims: The EINSTEIN-Extension trial (EINSTEIN-EXT) found that continued treatment with rivaroxaban for an additional 6 or 12 months (vs placebo) after 6–12 months of initial anticoagulation significantly reduced the risk of recurrent venous thromboembolism (VTE) with a small non-significant increased risk of major bleeding (none fatal or in critical site). This study aimed to compare total healthcare cost between rivaroxaban and placebo, based on the EINSTEIN-EXT event rates.

Methods: Total healthcare cost was calculated as the sum of treatment and clinical event costs from a US managed care perspective. Treatment duration and event rates were obtained from the EINSTEIN-EXT study. Adjustment on treatment duration was made by assuming a 10% non-adherence rate. Drug costs were based on wholesale acquisition costs. Cost estimates for clinical events (i.e. recurrent deep vein thrombosis [DVT], recurrent pulmonary embolism, major bleeding, clinically relevant non-major bleeding) were determined from the literature. Results were examined over a ±20% range of each cost component and over 95% confidence intervals (CIs) of event rate differences in deterministic (one-way) and probabilistic sensitivity analyses (PSA).

Results: Total healthcare cost was $1,454 lower for rivaroxaban-treated (vs placebo-treated) patients in the base-case, with a lower clinical event cost fully offsetting drug cost. The cost savings of recurrent DVT alone (–$3,102) was greater than drug cost ($2,723). Total healthcare cost remained lower for rivaroxaban in the majority (73%) of PSA (cost difference [95% CI]?=?–$1,454 [–$2,396, $1,231]).

Limitations: This study was conducted over the 1-year observation period of the EINSTEIN-EXT trial, which limited “real-world” applicability and examination of long-term economic impact. Assumptions on drug and clinical event costs were US-based and, thus, not applicable to other healthcare systems.

Conclusions: Total healthcare costs were estimated to be lower for patients continuing rivaroxaban therapy compared to those receiving placebo in VTE patients who had completed 6–12 months of VTE treatment.  相似文献   
29.
Natural resources influence economic performance through many different mechanisms, both beneficial and harmful. Some of these mechanisms tend to set in fast while others are rather slow. This suggests that pooling the long- and short-run effect as typical in the resource empirical literature may lead to incorrect inferences. This article provides an evaluation of the income contribution of natural resources using a panel cointegration approach that allows for short-run dynamic heterogeneity while imposing the restriction of long-run homogeneity. It finds, in a sample of developing countries over the period 1990–2012, that natural resources are a curse in the long run. The evidence is robust to alternative dynamic specifications, different measures and types of natural resource wealth, and controlling for regional effects.  相似文献   
30.
Like many emerging economies, the productive structure of the Paraguayan economy is not complex. It relies extensively on low value-added activities in the primary sector such as agriculture and cattle ranching. These activities have a lower return in terms of economic and social benefits than other potential productive activities and do not contribute to increasing capability accumulation. In this paper we present a tool to support the identification of strategic sectors and products which if taken advantage of, could leverage development through the accumulation of productive capabilities. Our guiding question is: Which productive sectors should be promoted to foster economic development in Paraguay through a transition towards a more complex economy? To answer this question, we use concepts from the Economic Complexity theory to identify new products and cluster them based on the Product Space methodology for the determination of potential products and combine it with the Analytic Hierarchy Process (AHP) for multicriteria analysis considering multiple criteria. In doing so, our proposed methodology contributes to both the Economic Complexity and the AHP literature. Through this combination, we tackle the multiplicity of juxtaposed criteria, which should be considered at the prioritization stage in the crafting of economic restructuring measures according to the country's capabilities. Our evaluation showed that the combination of the approaches is useful, and for Paraguay's case, it helped identify sectors, which, if promoted by policymakers, could help boost economic development through complexity and capability accumulation.  相似文献   
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