土地供应管制、住房供给弹性与房价周期波动

研究目的:分析土地供应管制通过住房供给弹性渠道对房价周期波动的影响。研究方法:理论分析,计量检验。研究结果:(1)土地供应管制影响房价波动的渠道是:土地供应管制的宽松和收紧通过供地规模、用地成本以及市场预期影响住房供给弹性,再经由供求关系和投机效应的传导影响房价波动。(2)土地供应管制可以解释45%的城市间住房供给弹性差异;地方政府不同松紧程度的策略性供地行为导致住房供给弹性与城市经济发达程度负相关,中央偏向中西部的土地配额管制政策导致东部城市住房供给弹性低于中西部城市。(3)住房供给弹性决定了房价周期波动,并具有非对称性效应:在市场景气繁荣阶段,供给弹性越小,房价涨幅就越大;在市场不景气阶段,房价跌幅与供给弹性的关系存在方向上的不确定性。研究结论:土地和住房领域供给侧改革的一个重点是改革供地制度和调整供地政策,使土地供应与住房需求在时空维度上相匹配,将有利于熨平房价波动,降低市场风险。     

土地供应规则的变化对北京市住宅用地市场的影响

研究目的:以2004年8月31日和2005年5月1日为界,将北京市住宅用地市场分为三个阶段,从土地供应量、地价、竞租曲线、土地—资本替代弹性等方面分析土地供应规则的变化对住宅用地招拍挂出让市场的影响。研究方法:定性分析,土地竞租曲线和土地—资本替代弹性分析。研究结论:(1)经营性项目用地招拍挂供应的政策对住宅用地市场的影响胜于“熟地”供应政策;(2)土地竞租曲线的变化反映土地市场在经过较大波动之后正在适应新的土地供应规则;(3)土地—资本替代弹性分析显示北京市住宅用地的市场效率仍然偏低。     

Estimation of time-varying price elasticity in 1970–1997 Japanese raw milk supply by structural time-series model

The price elasticity of raw milk supply in Japan is estimated over time by a structural time-series model in state space form, and the changes in elasticity are tested by the diagnosing test of de John and Penzer in 1998. The supply function is modeled with a local linear trend and a strictly exogenous autoregressive distributed lag price. The seasonality in the data is adjusted by a structural time-series model. In the 1970–1997 period, there were major dairy policy changes in Japan: a production adjustment, related penalties, and two-tier pricing. Hokkaido is the region that mainly provides the supply of raw milk for milk products, while Tofuken is the region that mainly produces drinking milk. The estimated price elasticity in Hokkaido became stable after imposition of the production adjustment. On the other hand, price elasticity in Tofuken became stable after the inflation of the mid-1970s. Price elasticity is estimated to be more inelastic as well as more likely to converge in inelasticity in Hokkaido than in Tofuken. We discuss the relationship between changes in dairy policy and changes in price elasticity.     

水产养殖经济研究文献综述

水产养殖业不仅是我国、而且是世界重要的食品供给部门,加强水产养殖的经济研究对促进其健康、持续、稳定地发展,保障全球食物供给、促进经济发展、提高从业者收入水平和消费者福利水平都有重要作用。本文在回顾国内外水产养殖经济研究文献的基础上,从研究方法、研究内容、研究品种等方面总结了其特征,指出国外以定量的实证研究、资源优化配置模型的构建等方法,在水产养殖技术经济分析、环境经济与可持续发展研究、资源的优化配置、产业发展战略与政策、水产品市场及其绩效等方面取得了较大进展,在贝类、虾类、三文鱼、罗非鱼、鲤科鱼类等主要养殖品种的经济研究成果尤为丰硕;国内水产养殖经济研究相对于国外同类研究及国内的农业经济研究存在较大差距。最后指出,水产养殖经济的学科构建、捕捞业与养殖业之间的相互关系、产业结构调整与优化、水产养殖生态经济效益、产业经济管理制度与政策研究等方面还存在众多需要突破的领域。     

Understanding the variation in estimates of off-farm labour supply elasticities: A meta-analysis

The design of rural development policies and government programmes in support of farm operations and farm households relies on precise estimates of off-farm labour supply elasticities. However, the wide variation in estimates dilutes their power to predict the magnitude of these targeted interventions. We perform a meta-analysis of estimates of off-farm labour supply elasticity to identify systematic factors that influence these estimates. A sample of 137 elasticities is obtained from 43 studies which use data ranging from 1960 to 2012. We examine theoretical assumptions, data availability and empirical specifications, and other study-specific characteristics. Controlling for potential publication bias, we estimate that the elasticity is approximately 0.64 to 0.77. Results of the analysis show that estimates are affected by modelling choices controlling for self-selection and life-cycle elements. However, we found no compelling evidence that study-specific characteristics of off-farm labour supply functions, including various measurements of labour supply, explain variation in the elasticities.     

中国木材进口的可替代性和进口来源安全性分析

基于2008—2017年中国与常年贸易伙伴国的数据样本,运用面板数据估计方法分别测算了国产原木、锯材与进口原木、锯材之间的Armington替代弹性,并分三阶段分组检验,还测算了中国原木、锯材主要进口来源国的出口产出弹性。结果显示:国产原木、锯材与进口原木、锯材之间具有较低的可替代性,且可替代性均呈下降趋势;内外材差异化程度较大,对国外进口木材具有长期的进口依赖性;原木进口市场供给风险较大,新西兰、澳大利亚供给安全性强,美国、巴布亚新几内亚、俄罗斯进口风险大;锯材进口市场的供给较稳定,泰国、巴西和马来西亚等国供给潜力大。因此,中国应大力发展培育国内优质大径材和珍贵树材,建设培育基地,提高优质木材供给能力;寻找珍贵木材的替代材料,通过技术开发生产替代产品;加强境外森林资源的开发利用,调整木材进口来源,减少对高风险国家的进口依赖。     

SUPPLY RESPONSE IN THE AUSTRALIAN EXTENSIVE LIVESTOCK AND CROPPING INDUSTRIES: A STUDY OF INTENTIONS AND EXPECTATIONS*

Most of the supply elasticity estimates reported for Australian agriculture are derived from equations estimated using time series data and incorporating ad hoc assumptions about price expectations. The authors' aim is to compare previously obtained supply elasticity estimates with those derived using theoretically more acceptable survey data on both producers' intentions and price expectations. Surveys were conducted in three regions in N.S.W., namely, the Southern Tablelands, the South-West Slopes and a portion of the Western Division centred on Cobar. The results of the research show that there are no major differences between the supply elasticities derived using the traditional time series approach and those obtained using the survey data. This finding is reassuring, given the cost of collecting survey data.     

基于生产要素视角的重庆市农业供给效率与发展潜力分析

目的 重庆市作为我国西部大开发重要的综合产业基地,探究该地区农业供给效率和农业发展潜力对促进农业可持续发展和农业政策制定具有积极意义。方法 文章以2001—2017年为研究时段,采用C-D生产函数模型对农业供给效率进行动态分析,采用熵权法构建农业发展潜力指数评价模型,并根据各地区农业发展潜力指数构建农业发展潜力竞争模型。结果 生产要素弹性分析结果表明2001—2017年农业劳动力弹性、农业土地弹性和化肥使用量弹性呈现负增长趋势,在农业供给侧结构中的贡献程度在逐渐减弱。农业资本弹性、农业机械总动力弹性和农业技术进步随着时间呈现增长的趋势,应该加大农业资本的投入,提高农业机械化程度,最大程度地提高农业生产效率。综合分析生产要素弹性和规模报酬指数,2001—2017年重庆市农业供给效率在不断提高。农业发展潜力指数分析结果表明2001—2017年全市农业发展潜力指数从47.15增长到60.13,各区县农业发展潜力指数也都呈明显的增长趋势。结论 重庆市农业经济增长方式已经由外延式增长方式逐渐转化为内涵式增长方式,农业经营方式从粗放型向密集型转化,农业供给效率在明显上升,各地区农业发展潜力指数在逐渐增加,经济发展程度对农业发展潜力具有明显的促进作用。     

EFFECTS ON FARM INCOMES AND RURAL LABOUR OF A RELATIVE INCREASE IN WAGES*

We use the concept of the elasticity of farm incomes with respect to changes in input prices to analyse the effects of a large increase in relative wages on selected measures of farm incomes. In order to estimate the elasticity of farm incomes we have to estimate elasticities and cross-elasticities of demand and supply for farm labour and capital. The estimates of elasticity of demand for operator and hired labour allow us to calculate the impact of a rise in wages on numbers of farmers and hired labour employed in agriculture.     

Tracing the evolution of the aggregate U.S. milk supply elasticity using a herd dynamics model

The U.S. dairy sector is characterized by increasing volatility of milk prices, and consolidation in production as evidenced by declining number of dairy farms with an increasingly larger share of milk supplied from a small number of very large farms. Using aggregate national data, we build a mixed‐frequency herd dynamics econometric model of the U.S. milk supply that updates and substantially amends the model first proposed by Chavas and Klemme. We implement a dynamic residual‐based bootstrap technique that can be used in testing for changes in nonmarginal simulated long‐run supply responsiveness, and trace the evolution of long‐run milk supply elasticity from 1975 through 2010. Several papers in the past have suggested that long‐run supply elasticity increases with dairy farm size, which implies that increased importance of large farms would increase aggregate long‐run supply responsiveness. Contrary to this conclusion, we find a declining trend in long‐run supply elasticity from 1975 through 2005. Persistence of such a decline would be a major cause for worry, as ever larger price swings would be needed to equilibrate the market in face of demand shocks. However, we find that milk supply is becoming more responsive since 2005 both to milk and feed price changes. Increasing responsiveness to feed prices further justifies focusing the next generation of the dairy policy instruments on managing dairy profit margins rather than just revenue streams.     

NEGATIVE SUPPLY RESPONSE AND THE ROLE OF PRICE EXPECTATIONS IN A TWO-PERIOD MODEL OF CATTLE PRODUCTION

This paper incorporates a representation of producers' price expectations (ARIMA) in a two-period production process to characterise short-run cattle supply. The model provides a framework for examining the role of biological factors and changing expectations of future cattle prices in generating a negative short-run supply response. The biological link between cattle generations requires the farmer to make a decision between production today and production tomorrow. This decision is based on a trade-off between the possibilities of increasing current profit levels by increasing current output weighted against the possibilities of increased future profit by maintaining animals in inventory under the expectation of future price increases. Application of the model to Canadian data for the period 1978-81 shows that the necessary condition for a negative supply response exists, but that the total supply elasticity remains positive.     

Imperfect competition,functional forms,and the size and distribution of research benefits

The effects of functional forms for supply and demand on the size and distribution of the returns to research are examined under a range of forms of competition. Under perfect competition, the choice of functional form is relatively unimportant for the estimation of research benefits. Under imperfect competition, the combination of the choice of functional forms for supply and demand and the nature of the research-induced supply shift can have profound implications for the results. Functional form plays a much more important role than in the competitive model. The most important contrast is between the constant elasticity model and the linear model (along with various cases of a generalized linear model). These findings are illustrated using a combination of analytical results and numerical simulations.     

PRODUCER BENEFITS FROM TECHNOLOGY INDUCED SUPPLY SHIFTS IN THE EC COTTON REGIME

This paper examines the effect of the current EC cotton regime on the level and distribution of potential benefits from technological change in cotton production in Greece and Spain. Results indicate that technical innovations in cotton production benefit producers but do not affect EC consumers and taxpayers. In addition, technical advances in cotton production result in important inter-country effects. These effects depend strongly on the relative magnitude of each country output and supply elasticity, the smaller producer (Spain) being in a riskier position. Finally, the current EC cotton regime, compared to a system which partitions the maximum guaranteed quantity between the two producer countries, benefits the innovative country.     

Tariff Equivalent of Technical Barriers to Trade with Imperfect Substitution and Trade Costs

The price-wedge method yields a tariff-equivalent estimate of technical barriers to trade (TBT). An extension of this method accounts for imperfect substitution between domestic and imported goods and incorporates recent findings on trade costs. We explore the sensitivity of this revamped TBT estimate to its key determinants (substitution elasticity, preference for home good, and trade cost). We use the augmented approach to investigate the recent Japan–U.S. apple trade dispute and find that removing the Japanese TBT would yield limited export gains to the United States. We then draw policy implications of our findings.     

基于Nerlove模型的玉米供给反应研究*——以吉林省为例

［目的］吉林省是以玉米为主要粮食作物的产量大省，吉林省玉米生产在保障国家粮食安全方面发挥着重要的作用。2016年国家取消玉米临时收储政策，实行“价补分离”政策（既市场化收购+补贴）。在玉米价格逐步市场化的形势下，为探究吉林省玉米种植面积对价格变动的反应程度，［方法］文章利用1985—2015年吉林省玉米种植面积、玉米平均出售价格、玉米的物质成本投入、玉米与大豆的每667m2收益比值、玉米与水稻的每667m2收益比值的时间序列数据，通过运用Nerlove模型，测算吉林省玉米播种面积对价格、物质成本、与大豆和水稻的每667m2收益比值的供给反应。［结果］吉林省玉米的短期供给弹性为049，长期供给弹性为063，短期供给弹性和长期供给弹性均小于1，缺乏弹性，吉林省玉米种植面积对价格变动的反应较为迟钝。［结论］提出完善农业耕作制度，推进玉米目标价格制度改革，优化玉米收购市场结构政策建议。     

Fishermen’s competitiveness and labour market performance: Evidence from shrimpers in Bangladesh

We conduct an experiment to determine competitiveness among shrimpers who engage in collecting shrimp seeds in the southwestern coastal region of Bangladesh. We then examine how competitiveness affects the labour supply decisions and labour market performance of these shrimpers. Our results show that shrimpers who prefer competition are more productive than shrimpers who do not prefer competition. Competitive shrimpers secure better prices and earn higher incomes selling their catches. We estimate that their wage elasticity of participation ranges from 0.4 to 0.5, which is consistent with preferences under neoclassical assumptions. Competitive shrimpers have a slightly greater wage elasticity than non-competitive shrimpers, suggesting that they might be more responsive to expected earnings. Our results have important policy implications for the efficient management of common pool resources.     

Inter‐ and intra‐seasonal crop acreage response to international food prices and implications of volatility

Understanding how producers make decisions to allot acreage among crops and how decisions about land use are affected by changes in prices and their volatility is fundamental for predicting the supply of staple crops and, hence, assessing the global food supply situation. This study makes estimations of monthly (i.e., seasonal) versus annual global acreage response models for the world's principal staple food crops: wheat, corn, soybeans, and rice. Primary emphasis is given to the magnitude and speed of the allocation process. Estimation of intra‐annual acreage elasticity is crucial for expected food supply and for input demand, especially in the light of the recent short‐term volatility in food prices. The econometric results indicate that global crop acreage responds to crop prices and price risks, input costs as well as a time trend. Depending on respective crop, short‐run elasticities are about 0.05 to 0.40; price volatility tends to reduce acreage for some of the crops; comparison of the annual and the monthly acreage response elasticities suggests that acreage adjusts seasonally around the globe to new information and expectations. Given the seasonality of agriculture, time is of an essence for acreage response. The analysis indicates that acreage allocation is more sensitive to prices in the northern hemisphere spring than in winter and the response varies across months.     

SUPPLY RESPONSE TO PRICE UNDER CERTAINTY,WITH REFERENCE TO THE UNITED KINGDOM EGG MARKET, 1954 TO 1966

Hen egg production in the United Kingdom expanded throughout the 1950's and early 1960's in the face of successive reductions in the guaranteed price thus raising questions about the efficacy of the guaranteed price system as a production control mechanism. The objective of this analysis is to estimate the guaranteed price elasticity of supply of hen eggs over the twelve-year period 1954 to 1966. Two models are used, a conventional linear form and a Nerlove type lagged model. The independent variables considered are the guaranteed price, the price of feed, and egg yield as a proxy for technology. The non-lagged equation is the more satisfactory and gives an elasticity value of 1.66, suggesting that flock owners were highly sensitive to changes in the guaranteed price. This sensitivity tended to be obscured by producer eagerness to profit from technological advance, which was the predominant factor affecting the scale of egg production over the period.     

DISTRIBUTED LAGS AND BARLEY ACREAGE RESPONSE ANALYSIS

The need to incorporate production response lags in agricultural supply models is established, and two such lags are considered: the familiar adaptive expectations geometric lag, and a more general polynomial lag. These distributed lag supply response models are applied to Australian barley data for the period 1946-47 to 1968-69. A number of statistical problems associated with the adaptive expectations model are discussed, and in particular it is concluded that lags both in the formation of price expectations and in acreage adjustment should be considered when using geometric lag models. While the polynomial lag model does not provide useful results in the present study, its simplicity and flexibility suggest it may be useful in other studies requiring distributed lag models. The short run and long run price elasticity of barley supply estimates are compared with Gruen et al. [14] supply elasticities for the other major rural commodities, from which it appears that barley has a higher short run elasticity but a lower long run elasticity than wheat, wool and meat.     

茶籽油供需影响因素与弹性分析

依据经济学的需求和供给的基本原理,首先从价格、收入、替代品的价格及可获得性、消费者偏好和购买者数量等因素对茶籽油市场需求特性进行分析;其次从投入品价格、技术进步、相关物品的价格、政府政策和气候条件等5个方面对茶籽油供给特征进行深入剖析;然后,对茶籽油需求价格弹性、需求收入弹性和供给价格弹性进行分析;最后提出相应的政策建议。