Soft drink prices,sales, body mass index and diabetes: Evidence from a panel of low-, middle- and high-income countries

We take advantage of four different cross-country datasets containing data on 78 countries for the period 1999–2014, in order to assess the relationship of carbonated soft drinks’ sales, as well as their prices, with body mass index (BMI), overweight, obesity and diabetes. Using an ecological study design and multivariate regression longitudinal estimation approaches, we find that carbonated soft drink sales were significantly positively related to BMI, overweight and obesity – but only in the low and lower-middle income countries. This finding was robust to a number of sensitivity and falsification checks. In this sub-sample, an increase in per capita soft drink sales by 1 litre per year was related to an increase of BMI by about 0.009 kg/m² (p < 0.1).. This is a small effect, implying that halving annual consumption per capita in this group of countries would result in a drop of BMI by only about 0.03 kg/m². Although soft drink prices were negatively related to weight-related outcomes in the sample of higher middle income and high income countries, this finding was not robust to falsification checks. The results thus suggest that sales restrictions to steer consumers away from soft drinks could indeed have a beneficial health effects in poorer countries, although the effect magnitude appears to be very small. However, given potential limitations of using ecological research design, results from individual level studies would be required to further ascertain the role of soft drink sales and prices in obesity and diabetes.     

Granting preferential market access in services sequentially versus jointly with goods

Despite the cost and resource‐effectiveness of joint trade negotiations and complementarities between goods and services‐trade flows, more than 12% of the 132 WTO‐notified services‐trade agreements (STAs) in force until August 2015 were entered into effect sequentially to goods‐trade accords. This stylised fact motivates our study of the determinants of joint versus sequential negotiation/accession of goods and services accords, a subject hitherto unexplored in the growing literature on the determinants of STA membership. Our results suggest larger marginal effects of fundamental economic, geographic, institutional, doing business and services regulatory factors on the propensity of joint negotiation/accession compared to STA formation alone. Moreover, cultural‐distance variables are only found to affect the likelihood of joint preferential liberalisation of goods and services trade, without influencing STA‐only membership.     

Analyzing the welfare‐improving potential of land in the former homelands of South Africa

This article contributes to the debate on the role of land in reducing poverty in rural South Africa. It uses the year of arrival in the former homelands as an instrument for land access and size. This identification strategy is based on the fact that African households were forcibly relocated to the homelands during the apartheid. Due to increasing population pressure, later arrivals were less likely to be assigned land. The results show that land has a large positive effect on household welfare. Because the homelands are relatively disadvantaged areas, these results provide a lower bound for the positive effects of land on household welfare.     

基于高光谱曲线的马铃薯与其他主要作物光谱差异性分析

[目的]文章以马铃薯关键生长期——结薯期为测量时点,以马铃薯和玉米、大豆、水稻为研究对象,开展高光谱曲线特征差异性研究。[方法]为更好地描述马铃薯与其他作物的光谱差异,创建高光谱反射率差异性指数、高光谱一阶导数差异性指数、高光谱红边幅值差异性指数、高光谱曲率差异性指数及高光谱植被指数差异性指数。[结果](1)马铃薯与玉米、大豆、水稻3种作物光谱曲线具有明显差异,马铃薯与玉米的反射率值在480nm附近蓝色波段位置差异最显著,差异性指数值为67.866%,与大豆、水稻的最大差异性指数值分别为49.068%、57.559%,均位于550nm附近绿色波峰位置;(2)作物光谱曲线经一阶导数变换运算,马铃薯与其他作物间的光谱差异被显著放大,在近红外波段放大程度最显著;(3)马铃薯与玉米、大豆、水稻高光谱曲率差异性指数最大值均位于波长750nm附近,差异性指数值分别为78.365%、63.471%、80.882%;(4)常用植被指数中,比值植被指数、增强型植被指数可显著区分马铃薯与玉米、大豆、水稻。[结论]差异性分析结果为农作物空间分布遥感识别提供了技术支撑。     

Relationship between oil,stock prices and exchange rates: A vine copula based GARCH method

In this paper, we apply a vine copula approach to investigate the dynamic relationship between energy, stock and currency markets. Dependence modeling using vine copulas offers a greater flexibility and permits the modeling of complex dependency patterns for high-dimensional distributions. Using a sample of more than 10 years of daily return observations of the WTI crude oil, the Dow Jones Industrial average stock index and the trade weighted US dollar index returns, we find evidence of a significant and symmetric relationship between these variables. Considering different sample periods show that the dynamic of the relationship between returns is not constant over time. Our results indicate also that the dependence structure is highly affected by the financial crisis and Great Recession, over 2007–2009. Finally, there is evidence to suggest that the application of the vine copula model improves the accuracy of VaR estimates, compared to traditional approaches.     

Competition and efficiency in the MENA banking region: a non-structural DEA approach

The goal of this article is to empirically assess the relationship between competition and efficiency in the banking sector of Middle East and North African (MENA) countries spanning the period 1997–2011. To measure the level of competition, the article estimates the non-structural indicator known as the H-statistic, while the level of bank efficiency is estimated through the nonparametric methodology of the Data Envelopment Analysis (DEA) and the Bootstrap Data Envelopment Analysis (BDEA), respectively. The empirical results are robust under six econometric methodologies, providing sufficient evidence for the presence of a one-way (negative) Granger causality, running from efficiency to competition. The empirical findings lead to the rejection of the ‘Efficient Structure Hypothesis’, implying that increases in competition do not precede increases in cost efficiency.     

Productivity changes in pre-crisis Western European banks: Does scale effect really matter?

Insofar as the completion of the Single Market for Financial Services, it has presented new challenges for European Banking industries. In this study, we use a recently developed generalized metafrontier Malmquist productivity index (gMMPI) to provide insights on productivity growth. We extend the gMMPI to broaden the index's capacity by decomposing various sources of productivity change in the metafrontier context. The sample contains commercial banks from 12 Western European countries prior to the recent financial crisis. A key advantage of our extension is that it introduces the role of scale effects. The empirical results show that an average bank's productivity growth arises mainly from technical changes and scale effects. Moreover, smaller and larger banks grow faster than medium ones. In addition, conservative banks tend to grow faster. These findings suggest that a more competitive and integrated financial market induced by financial deregulation is indeed able to improve banks’ productivity.     

On the Opportunity Cost of Crop Diversification

Distance functions are increasingly being augmented, with environmental goods treated as conventional outputs. A common approach to evaluate the opportunity cost of providing an environmental good is the exploitation of the distance function's dual relationship to the value function. This implies that the opportunity cost is assumed to be non‐negative. This approach also requires a convex technology set. Focusing on crop diversification for a balanced sample of 44 cereal farms in the East of England for the years 2007–2013, this paper develops a novel opportunity cost measure that does not depend on these strong assumptions. We find that the opportunity cost of crop diversification is negative for most farms.     

巴中市农田土壤重金属分布及生态风险评价

[目的]通过测定秦巴山区巴中市农田土壤中镉(Cd)、铅(Pb)、锌(Zn)3种重金属元素的含量及分布特征,为农田重金属防治科学决策的制定提供数据支撑。[方法]文章采用内梅罗指数和潜在生态风险指数来综合评价巴中市土壤重金属污染状况。[结果]巴中市农田土壤锌平均含量比四川省丘陵地区背景值高6.78%,而镉和铅含量均未超出其背景值,总体评价良好,但各检测点之间差异较大,镉含量最多超出背景值5.7倍。内梅罗指数评价结果显示,全市平均综合污染指数为1.10,接近清洁状态。潜在生态风险指数评价结果显示,其最小值为15.94,最大值为177.74,平均值为35.38。[结论]巴中市农田土壤重金属污染状况基本处于低度风险级别,但各地块污染程度不尽一致,应因地制宜,采取适当措施治理土壤污染。     

基于供给侧的贵州省生态农业绩效评价

［目的］随着供给侧改革的推进，贵州省生态农业发展迅速，为了实现生态农业的可持续发展，对生态农业发展效益进行客观地评价具有重要意义。［方法］文章以贵州省9个市（州）的生态农业数据为研究对象，构建贵州省生态农业绩效指标评价体系，利用因子分析法对贵州省9个市（州）的生态农业数据进行主成分分析，计算每个地区的综合得分情况。［结果］通过对贵州省生态农业绩效构建评价指标体系，从社会投入与产出、耕地投入与产出两个方面来进行评价。各市（州）综合得分结果表明遵义市和毕节市的得分最高，分别为4456 595万和4388 418万； 六盘水市和贵阳市的得分比较低，分别为1572 071万和1621 515万。［结论］贵州省各市（州）生态农业发展存在较大的地区差异性，遵义市和毕节市的生态农业效益最好，安顺市、六盘水市、贵阳市的生态农业建设相对较弱。因此，贵州省应该加强政策引导、利用先进技术、加大生态农业的投入，从各方面促进生态农业的可持续发展。