中国股市个股非流动性、换手率和短期反转的关系

本文在排除买卖报价反弹、周末效应等干扰因素的前提下,利用分组构建逆势投资组合及Fama-Macbeth回归方法,研究周期下我国股市中的短期收益反转现象。实证结果表明：我国股市中存在短期收益反转现象,短期反转在股票输家中表现更为明显;股票收益的短期反转随着非流动性的增强而增强;我国股市具有极高换手率的投资组合表现出特殊性,极高换手率对股票输家的短期收益反转具有抑制作用,而对股票赢家的短期收益反转具有促进作用。     

Estimating liquidity premia in the Spanish government securities market

This paper investigates the presence of liquidity premia in the relative pricing of assets traded on the Spanish government securities market. First, a classification of bonds into four different categories based on their degree of liquidity is proposed. Second, liquidity premia are estimated introducing liquidity parameters in the estimation of the zero-coupon yield curve. Results suggest the existence of a liquidity premium for post-benchmark bonds (both strippable and non-strippable). The size of this premium is relatively small. In the case of pre-benchmark bonds, the lack of liquidity does not seem to be priced. It is also shown that these pricing discrepancies are robust to the impact of taxes on bonds.     

The Tourinho model: neglected nugget or a receding relic?

This article evaluates Tourinho's (1979b Tourinho, O. A.F. 1979b. “The valuation of reserves of natural resources: an option pricing approach”. Berkeley: University of California. PhD thesis [Google Scholar]) work as one of the earliest contributors to the real options literature. His model pioneered the application of risk neutrality to uncertain investments, but his originality of introducing an option-holding cost albeit to overcome the extraction paradox is rarely imitated. We claim that the combination of a convenience yield and an option-holding cost produces a more satisfying representation. Moreover, variations in the holding cost give rise to a host of investment decisions ranging from the standard real option solution for a zero-holding cost to a net present value solution for an infinite-holding cost. Not only does the holding cost mediate between these two poles, but it provides the option seller (usually a landowner or a government) with a policy instrument for influencing the extraction timing and thus the extraction profit of the option buyer. We derive the holding cost that optimizes the landowner's combined value of the option premium, holding costs and eventual royalties.     

Measuring the natural yield curve

We generalize the concept of the natural rate of interest (Laubach and Williams, 2003; Woodford, 2003) by defining and estimating the natural yield curve (NYC) – the term structure of natural interest rates. Our motivation stems i.a. from the observation that at times when central banks attempt to directly affect long-term interest rates (e.g. via quantitative easing) the gap between the short-term real and natural rate is no more a good indicator of the monetary policy stance. We estimate the NYC on US data, document its main properties and show i.a. that in the period 2008 to 2011 the NYC allows to better capture the US monetary policy stance than the short-term natural rate.     

The effects of domestic rice market interventions outside business-as-usual conditions for imported rice prices

The Philippine government intervenes in the domestic rice market through the imposition of import tariffs and the provision of producer and consumer subsidies. While policymakers are aware that these programmes come with allocative efficiency costs, they justify the programmes on the grounds that they insulate the domestic economy from unexpected price spikes in the international rice market. An interesting matter for policy evaluation is to quantify the insulation benefit that the programmes provide in circumstances of sudden severe import price spikes. To examine this question, we undertake a dynamic computable general equilibrium (CGE) simulation in which the Philippines is subject to an external rice price shock. We find that the insulation benefit of the support programmes under a 2008-like event is worth approximately 0.10% of real consumption. However, the cost of insuring against these price spikes is significant. We estimate the annual cost of the rice market interventions at approximately 0.40% of real consumption.     

The determinants of trade credit use: the case of the Tanzanian rice market

Most small businesses in the developing economies suffer from a lack of access to formal external finance. One important alternative source of finance for these entrepreneurs is trade credit. Applying a unique data-set containing data on specific trade relations between rice wholesalers and rice retailers in Tanzania, we analyse the determinants of trade credit demand and supply in this market, using a simultaneous equation modelling approach. The analysis shows that while the demand for trade credit is primarily determined by the extent to which retailers need external funds, supply is mainly driven by wholesalers’ incentives to attract and keep clients. Moreover, wholesalers’ willingness to provide credit increases if they have better information about the possibility that the customer will fail to repay the credit.     

The Potential Market for GM Rice with Health Benefits in a Chinese High-Risk Region

Genetically modified rice with a high folate content, i.e., folate biofortified rice, was recently developed to tackle folate deficiency. A consumer segmentation study is conducted to explore its market potential in the Chinese Shanxi Province, where the burden of folate deficiency is among the world’s highest. Cluster analysis of 451 rice consumers identified three segments: enthusiasts (14.2%), cautious (41.2%), and opponents (44.6%). Enthusiasts obtain the highest score of GM food knowledge and attitudes and have the highest GM rice acceptance rate, followed by cautious and reluctant consumers. Regarding GM food information, enthusiasts use almost entirely audiovisual channels and rely more on the industry, while other segments depend more on informal channels and anti-GM sources. Trust levels in these channels/sources differ between enthusiasts (high), opponents (neutral), and cautious (low). Based on multinomial regression, a targeted communication approach is recommended with a focus on female, cautious consumers and rural, low-educated opponents.     

Transmission of Rice Prices from Thailand into West African Markets: The Case of Benin,Mali, and Senegal

ABSTRACT

The integration of West African rice market to the world market is assessed in order to derive the implication for food security. To this end, the transmission of rice price changes on the world market to selected markets in West Africa was examined to test for the presence of transaction costs. Using the two-regime threshold cointegration procedure on monthly price data, evidence in support of the hypothesis of asymmetric price transmission was found between Thailand and some West African markets. Price increases on the world market were more quickly transmitted to domestic price than were price decreases in Benin and Mali, suggesting short-run dynamic inefficiencies and the presence of transaction costs. In Senegal, the adjustment was linear, suggesting greater integration with the world rice market. The results suggest that West African governments should design and implement adequate policies to develop the domestic rice sector, improve market infrastructures in order to reduce their country dependency to international markets and ensure food security.     

高水分稻谷春季通风干燥试验

春季收购的新粳稻谷由于水分偏高,采用在粮库内铁路专用线站台上包打围临时储存,利用二机二风道先行降水到15．5％以后,再转入高大平房仓,利用谷物冷却机平衡水分、粮温,使其安全过夏;与烘干相比,能增收节支,实现高水分粳稻安全储藏,提高粮库经济效益。     

不同水稻品种对钒的积累及化学形态

通过盆栽试验,研究了钒（V）胁迫下不同品种水稻植株中钒的积累和化学形态。结果表明,不同品种水稻各器官中V的分布为根＞茎＞叶＞子实,两种水稻品种吸收的V主要富集在根部。水稻生长期新优188水稻各器官中V的浓度均低于十优838水稻,如在V处理浓度为100 mg·kg-1时,在分蘖期、扬花期、灌浆期和成熟期,新优188水稻植株根中V含量分别为73.10、92.56、57.46、57.81 μg·g-1,茎叶中为8.79、4.52、2.13、2.56 μg·g-1;十优838水稻植株根中的V含量为59.14、94.93、88.59、89.70 μg·g-1,茎叶中为4.64、3.66、2.29、3.24 μg·g-1。推断十优838水稻较新优188水稻有较强的V吸收能力。两种水稻品种中,根部V主要以活性较低的盐酸提取态（FHCl）和醋酸提取态（FHAc）为主,茎和叶中V主要以盐酸提取态（FHCl）和水提取态（Fw）为主,认为V在水稻根部多以难溶于水的重金属磷酸盐或草酸盐而被固定,限制了水稻中V转移到茎和叶,从而避免了高浓度V对植物光合作用及其他生理过程的干扰。