南方丘陵区新增耕地质量空间特征研究*——以江西省宜春市为例

［目的］粮食安全的根本是在耕地，关键在于耕地质量。目前新增耕地主要源于土地开发项目、城乡建设用地增减挂钩土地复垦项目等，这些新增耕地需要对其开展耕地质量等别评定工作，了解新增耕地的质量状况，分析其空间特征，这对落实国家耕地保护制度、开展农村土地整治工作等具有重要作用。［方法］文章以南方典型丘陵区域——江西省宜春市作为研究区域，在新增耕地质量评价的基础上，运用地统计学、景观生态学、Arcgis空间分析技术和典型相关分析方法，研究宜春市新增耕地质量的空间特征，掌握耕地质量等别的分布规律，了解耕地质量的影响因素，为制定合理的耕地资源利用与保护政策提供依据。［结果］（1）Moran′s I值结果表明宜春市2014年新增耕地利用质量在空间分布上的空间自相关性最强，而耕地自然质量空间自相关性最弱。（2）景观破碎度指数结果表明优、高等别的新增耕地质量破碎度大于中、低等别的； 多样性指数结果表明新增耕地质量多样性指数比较大； 优势度指数结果表明新增耕地质量等别优势度指数比较小，与多样性指数结果相呼应； 均匀度指数结果表明，新增耕地质量等别均匀度指数相差不大，新增耕地质量等别比较均匀。（3）质心结果表明2013—2014年间宜春市新增耕地质量的格局整体上是向西南方向变化。［结论］宜春市新增耕地质量不高； 新增耕地的利用水平差异性较小，自然本底状况差异较大； 新增耕地质量等别类型多，各质量等别类型耕地均有增加，耕地质量参差不齐，较高等地的新增耕地相对低等地而言更破碎化； 新增耕地的开发格局向着西南方向移动； 该研究为南方丘陵区的新增耕地保护提供了一定的参考依据。     

Combining wavelet decomposition with machine learning to forecast gold returns

This paper combines the discrete wavelet transform with support vector regression for forecasting gold-price dynamics. The advantages of this approach are investigated using a relatively small set of economic and financial predictors. I measure model performance by differentiating between a statistically-motivated out-of-sample forecasting exercise and an economically-motivated trading strategy. Disentangling the predictors with respect to their time and frequency domains leads to improved forecasting performance. The results are robust compared to alternative forecasting approaches. My findings on the relative importances of such wavelet decompositions suggest that the influences of short-term and long-term trends are not stable over the full evaluation period.     

How justified is abandoning money in the conduct of monetary policy in Australia on the grounds of instability in the money‐demand function?

The role of money in the design and conduct of monetary policy has reemerged as an important issue in both advanced and developing economies, especially since the 2007 global financial crisis. A growing body of recent literature suggests that the causal relationship between money supply growth and inflation remains intact across countries and over time and that this relation is not conditional on the stability of the money‐demand function or whether money is endogenous or exogenous. Moreover, critical for a rule‐based monetary policy is the presence of a long‐run stable money‐demand function, rather than a short‐run money‐demand model that may exhibit instability for many reasons, including problems with estimating a money‐demand model with high‐frequency data. Provided that a stable money‐demand function exists, it could be useful to establish long‐run equilibrium relations among money, output, prices, and exchange rates, as the classical monetary theory suggests. Within this analytical framework, this paper addresses the question of whether money has any role in the conduct of monetary policy in Australia. The conventional wisdom is that the money‐demand function in Australia has been unstable since the mid‐1980s due to financial deregulation and reforms; this led to a change in the strategy of monetary policy for price stability in the form of inflation targeting that ignores money insofar as inflation and its control are concerned. This paper reports empirical findings for Australia, obtained from a longer quarterly data series over the period 1960Q1–2015Q1, which suggest that instability in the narrow‐money‐demand function in Australia was primarily due to the exclusion of variables which have become important in the deregulated environment since the 1980s. These findings are confirmed by an expanded form of the narrow‐money‐demand function that was found stable over the past two decades, although it experienced multiple structural breaks over the study period. The paper draws the conclusion that abandoning the monetary aggregate as an instrument of monetary policy in Australia, under a rule‐based monetary policy such as inflation targeting, cannot be justified by instability in the money‐demand function or even by lack of a causal link between money supply growth and inflation.     

加强师德师风建设提高以德治校能力

教育大计，教师为本；教师培养，师德师风为先。师德师风建设是高校思想政治教育的重要内容，是进一步推动廉政文化进校园工作的重中之重，是增强以德治校水平和提高以德治校能力的关键，是贯彻落实学校党风廉政建设和深入推进反腐败工作的重要举措。     

Using the Pack‐and‐a‐Half Rule to Eliminate Backroom Inventories in Retail Operations

In the retail industry, backroom inventories are typically associated with higher labor costs and greater operational complexity. Thus, retailers look for ways to eliminate backroom inventories. A heuristic used for this purpose is the pack‐and‐a‐half rule which suggests that the shelf space allocated for a product should be at least 50% larger than the case pack quantity in which the product is delivered. Despite its popularity among retailers, the pack‐and‐a‐half rule has been ignored in the academic literature. We introduce the pack‐and‐a‐half rule, assess its impact on a retailer's profits, identify cost, demand, and product characteristics driving this impact, and propose a modification. Based on an analysis of data obtained from a retailer on 1,986 SKUs in 20 categories, we find that the pack‐and‐a‐half rule decreases a retailer's profits, on average, by 10% when applied uniformly across all SKUs. Further, this decrease is significantly affected by product depth, product width, demand elasticity, case pack quantity, and inventory carrying cost. Finally, we develop a set of modifications based on these variables where the pack‐and‐a‐half rule is applied selectively and in a stepwise fashion. These modifications limit the decrease in a retailer's profits to a range between 6% and 7%.     

An Exploratory analysis of flight delay propagation in China

Delay propagation is the flight departure delay caused by the arrival delay of pre-segment flight. Chinese airline market has suffered very poor on-time performance (OTP) in recent years. It is, however, unclear whether delay propagation prevails as one major source for such problem. This study first aims to empirically quantify delay propagation in the Chinese airline market. Specifically, we shed light on heterogenous levels of delay propagations across different airports and airlines. Then, the distinct delay propagation patterns in China are also discussed and compared with other developed airline markets (e.g., the US and Europe). Our estimation is based on OTP data for over 12 million Chinese flights covering the 2015–2017 period. Specifically, it is found that 10 min arrival delay of pre-segment flight within 1 hr before the departure lead to an average of 7.49 mins delay propagation for subsequent departure flight. Arrival delay of earlier pre-segments (1–2 and 2–3 hr before the departure) leads to much less delay propagation, due to longer ground buffer. Chinese airlines arrange longer ground and flight buffer than that of the US airlines to prevent the delay propagation from accumulating along the subsequent flights in a day. Thus, unlike the US market, delay propagation is not the major reason for poor OTP in China. In addition, delay propagation is less prevailing at the Chinese hub airport. This is because China has relied on point-to-point network, which does not require sophisticated schedule coordination. And the local passengers at these Chinese hub airports have higher time value such that the Chinese airlines also try to improve OTP at these hub airports to better serve these lucrative but time-sensitive local passengers. Unlike the European LCCs, Spring Airlines, the largest low-cost carrier (LCC) in China, outperforms major full-service carriers (FSCs) in controlling delay propagation. This finding may also apply to other Northeast Asian LCCs sharing common operational characteristics as Spring Airlines. Last, we find that airlines purposely tolerate moderate departure delays of up to 15 min, which is the threshold that defines delays, no matter whether the pre-segment flight arrives late or on-time. The relevant policy and managerial implications are also discussed.     

A product-centric data mining algorithm for targeted promotions

Targeted promotions in retail are becoming increasingly popular, particularly in UK grocery retail sector, where competition is stiff and consumers remain price sensitive. Given this, a targeted promotion algorithm is proposed to enhance the effectiveness of promotions by retailers. The algorithm leverages a mathematical model for optimising items to target and fuzzy c-means clustering for finding the best customers to target. Tests using simulations with real life consumer scanner panel data from the UK grocery retailer sector show that the algorithm performs well in finding the best items and customers to target whilst eliminating “false positives” (targeting customers who do not buy a product) and reducing “false negatives” (not targeting customers who could buy a product). The algorithm also shows better performance when compared to a similar published framework, particularly in handling “false positives” and “false negatives”. The paper concludes by discussing managerial and research implications, and highlights applications of the model to other fields.     

Does the Reserve Bank of Australia follow a forward-looking nonlinear monetary policy rule?

ABSTRACT

The conventional monetary policy rule describes a simple linear relationship between the domestic interest rate, inflation rate and output gap. An important extension to this rule is to incorporate the forward-looking behaviour of central banks, where it is assumed that they target an expected level of inflation instead of its current realised value. Using quarterly observations for the period 1993:1-2018:2, this paper investigates whether the conduct of monetary policy in Australia can be described by a forward-looking linear monetary policy rule, or by a nonlinear forward-looking monetary policy rule. In particular, the nonlinear forward-looking monetary policy rule is analysed in a regime-switching framework using a smooth logistic transition regression model. While the results show that the conventional forward-looking linear monetary policy rule describes the application of monetary policy in Australia reasonably well, the interest rate setting behaviour of the RBA is best described by a nonlinear forward-looking monetary policy rule.     

现代治理视域下行政审批机构改革研究

推进行政审批机构改革是新时代完善现代国家治理体系和提升现代国家治理能力的必然要求。行政审批局改革模式的现代治理意涵在于优化配置制度建设主体要素以及重构革新治理主体组织结构,并在制度依据、机制运行和治理效能三个层面建构起改革运行机理。尽管通过集中审批权限、实现"一枚印章管审批"大力提升了审批效率,但行政审批局模式依然面临有悖"职权法定"、纵横协调不足、制度建设不充分和资源配置不合理的四重困境。现代治理视域下,应从树立科学合理的审批改革理念、完善行政审批机构改革的顶层设计以及创新行政审批局具体工作模式等方面不断完善和深化行政审批机构改革。     

Macroeconomic adjustment with managed exchange rates and capital controls: Some lessons from China

This paper examines the performance of capital controls and exchange-rate management when the economy finds itself in dark corners. These are times when the real sector experiences a sequence of prolonged negative shocks from world demand, while the central bank faces low world interest rates on its foreign-exchange reserve holdings. We examine two regimes, one of a fixed exchange rate with strong capital controls and another with a more open capital account with a managed exchange rate. We show how this model replicates recent experiences of China as it moved from a relatively fixed exchange rate regime with strong capital controls to a more flexible exchange rate regime with a more open capital account. Our results show that capital-account liberalization should be accompanied by domestic price liberalization to avoid large losses in foreign exchange reserve and jumps in unemployment during dark corners in the more open regime.