Inequalities of opportunity in the access and use of telecommunication services in Togo

The liberalization of the telecommunications sector in Togo aimed at ensuring access to a better quality of telecommunication services at affordable prices to everyone. While the liberalization policy has increased competition in the sector and reduced significantly telecommunication services prices charged to costumers, statistics on the access and use of telecommunication services in Togo reveal disparities with respect to individuals' socio-economic characteristics which could be an indication of the existence of inequalities of opportunities in the access and use of these services.This paper investigates the inequalities of opportunity in the access and use of telecommunication services in Togo using a parametric approach. The results of estimations indicate that, inequalities of opportunities are larger for men and the elderly than respectively women and youths and are more pronounced in urban areas and regions such as the Plateaux and Savanna regions. Moreover, the circumstance variables such as the ‘place of residence’ and the ‘region’ are the key variables in explaining the inequalities of opportunities in the access and use of telecommunication services in Togo. So, policies toward reducing inequalities of opportunity in the access and use of telecommunication services in Togo should be designed with regards to men, the elderly, and people living in urban areas and regions such as the Plateaux and Savanna regions.     

Effects of employees’ opportunities to influence in-store music on sales: Evidence from a field experiment

The effects of in-store music on consumer behavior have attracted much attention in the marketing literature, but surprisingly few studies have investigated in-store music in relation to employees. By conducting a field experiment in eight Filippa K fashion stores in Stockholm, Sweden, we investigate whether it is beneficial for store owners to give employees more opportunities to influence the in-store music. We randomly assigned the stores into a treatment group and a control group, with the employees in the treatment stores having the opportunity to influence the in-store music through an app developed by Soundtrack Your Brand (SYB). The experiment lasted 56 weeks and sales data were also gathered 22 weeks before the experiment, resulting in a total of 4626 observations. Our results show that sales decreased by 6% when the employees had the opportunity to influence the music played in the store, and the effect is driven by a reduction in sales of women's clothing. Interviews with the employees revealed that they had diverse music preferences, frequently changed songs, and preferred to play high-intensity songs. Employees thus seem to make choices regarding the in-store music that reduce sales, implying that store owners might want to limit their opportunities to influence the background music.     

How does reinsurance and derivatives usage affect financial performance? Evidence from the UK non-life insurance industry

A three-equation structural model is applied in this study to facilitate our examination of 1994–2011 regulatory returns data on UK non-life insurers, from which we find that those insurers using more reinsurance tended to have inferior financial performance, whilst those insurers with a predisposition towards risk management tended to have used both reinsurance and derivatives. We also find that those insurers with high loss ratios were found to have inferior financial performance. Our analysis sheds some light on the relationships between financial performance, reinsurance and derivative usage.     

Exploring the mismatch between credit ratings and loss-given-default: A credit risk approach

It is commonly observed that high grade loans with better ratings are often associated with low recoveries if they default (i.e. with relatively high loss-given-default (LGD)). To address the mismatch problem, this paper proposes a credit risk approach by minimizing LGD for higher rated loans as a risk-rating matching standard in the sense that the decreasing LGD from creditors’ perspective is associated with higher credit rating for the borrower. This standard forces customers’ credit rating of each grade to be optimally determined in correspondence to its LGD, which means the LGD of high grade loans tends to be low. The approach is then tested using three credit datasets from China, i.e. credit data from 2044 farmers, 2157 small private businesses and 3111 SMEs. The empirical results show that the proposed approach indeed guides the way to solve the mismatch phenomenon between credit ratings and LGDs in the existing credit rating literature. By optimally determining credit ratings, the findings derived from this paper help provide a valuable reference for bankers, and bond investors to manage their credit risk.     

What drives cross-country differences in export variety? A bilateral panel approach

A worldwide event like the 2020 Coronavirus outbreak can only reinforce the interest in modelling trade diversification as a key factor in countries’ vulnerability to external shocks. This paper adopts a detailed relative framework to study the determinants of product-level export variety in a large bilateral panel of developing and developed economies (16,770 country pairs in the period 1988–2014). We find that country pairs characterized by large differentials in productivity and in the makeup of the labour force differ in export variety patterns. This result holds after controlling for other endowments and for trade costs. Further, productivity plays a significant role in the reduction of export variety dissimilarities between countries belonging to different income groups. Hence, without successful technological convergence the low-income economies will not be able to reduce their exposure to export risk.     

The effect of observables,functional specifications,model features and shocks on identification in linearized DSGE models

The decisions a researcher makes at the model building stage are crucial for parameter identification. This paper contains a number of applied tips for solving identifiability problems and improving the strength of DSGE model parameter identification by fine-tuning the (1) choice of observables, (2) functional specifications, (3) model features and (4) choice of structural shocks. We offer a formal approach based on well-established diagnostics and indicators to uncover and address both theoretical (yes/no) identifiability issues and weak identification from a Bayesian perspective. The concepts are illustrated by two exemplary models that demonstrate the identification properties of different investment adjustment cost specifications and output-gap definitions. Our results provide theoretical support for the use of growth adjustment costs, investment-specific technology, and partial inflation indexation.     

Overcapacities in banking: Measurement,trends and determinants

Global banks face profitability challenges since the global financial crisis. Besides cyclical factors, structural features such as overcapacities have been identified as root causes. While policymakers agree on the need for bank consolidation, there is less consensus on the definition and measurement of overcapacities in banking. This paper contributes by conceptualising and formalising the different dimensions of overcapacities in banking and by constructing a novel measure thereof. In addition, it empirically tests the main determinants of overcapacities in banking from 2006 to 2017 and assesses their relative importance. The results indicate that non-bank competition, the interest rate environment and bank business models are the most important driving factors of banking sector overcapacities. This is because shadow banks, benefitting from regulatory arbitrage, have altered banks’ capacity needs, low rates compressed margins and increased pressure to improve cost efficiencies, and retail-oriented business models have operated extensive branch networks entailing heavy fixed costs.     

Modelling demand for lotto using a novel method of correcting for endogeneity

Modelling lottery sales as a function of the mean, standard deviation and skewness of the probability distribution of returns potentially gives insights into how the design of a game could be modified to maximise net revenue. But use of OLS is problematic because the level of sales itself affects values of the moments (and insufficient instruments are available for IV regression). We draw on the concept of a rational expectations equilibrium, developing a new regression model which corrects for endogeneity where the causal impact of the dependent variable on the right-hand side variables is deterministic. We apply the model to data on lotto sales from Spain. Using the Spanish data, we show that results provide more reliable guidance to lottery agencies because accounting for endogeneity leads to significantly different results from OLS and these results have superior performance in out-of-sample forecasting of sales. More generally, results prove consistent with the Friedman-Savage explanation of why people buy lottery tickets and with evidence from racetrack data that ‘bettors love skewness’.     

全空域球面相控阵波束形成器的优化设计

针对目前全空域球面相控阵测控系统工程应用中波束数量、信号瞬时带宽等数字波束形成器性能和复杂度难以兼顾的问题，分析了常规波束形成方法在基于半球形结构的S频段大型共形天线阵列工程应用中的局限，给出了一种基于子阵划分的宽带数字波束形成器优化设计方法，通过优化幅相和时延补偿方式，使算法不受子阵尺寸限制，工程实现复杂度较低。系统建模和仿真验证表明该方法可以获得良好的瞬时带宽性能，具有较好的工程应用价值。     

空间信息传输中的多天线技术综述

近年来，空间信息传输中的多天线技术得到了广泛关注和大量研究。首先介绍了多天线技术的信息论基础和演进过程；然后综述了多天线通信和雷达技术的研究进展，包括多输入多输出(Multiple-Input Multiple-Output,MIMO)卫星通信技术、深空天线组阵技术、空间多维协同传输理论与技术、MIMO雷达技术和分布式孔径相参合成雷达技术，分析了其中的关键技术及未来可研究的方向；最后，总结了多天线技术在航天测控领域应用的优势，展望了基于多天线的测控技术。