Public Debt Sustainability in Africa: Building Resilience and Challenges Ahead

The increased access of African countries to international capital markets has put public debt sustainability at the forefront of the continent's policy agenda. Utilising the ‘stabilising primary‐balance’ approach, this article finds that the actual primary balances exceeded those required to keep public debt at the 2007 level in about half the countries studied, and in several cases, those needed to reduce public debt‐to‐GDP to sustainable thresholds. The interest rate‐growth differential (IRGD) drove sustainability, underscoring the importance of growth and borrowing for growth‐enhancing outlays. As the IRGDs are likely to narrow over the longer term, fiscal policies will need to play a greater role.     

Analyzing time–frequency relationship between oil price and exchange rate in Pakistan through wavelets

This study analyzed the time–frequency relationship between oil price and exchange rate for Pakistan by using measures of continuous wavelet such as wavelet power, cross-wavelet power, and cross-wavelet coherency (WTC). The results of cross-wavelet analysis indicated that covariance between oil price and exchange rate is unable to give clear-cut results, but both variables have been in phase and out phase (i.e. they are anti-cyclical and cyclical in nature) in some or other durations. However, results of squared wavelet coherence disclose that both variables are out of phase and real exchange rate was leading during the entire period studied, corresponding to the 10–15 months’ scale. These results are the unique contribution of the present study, which would have not been drawn if one would have utilized any other time series or frequency domain-based approach. This finding provides evidence of anti-cyclical relationship between oil price and real effective exchange rate; however, in most of the period studied, real exchange rate was leading and passing anti-cycle effects on oil price shocks which is the major contribution of the study.     

论反垄断私人诉讼原告资格的二元化

我国当前民事诉讼立法对适格原告的要求过于严格,无法契合反垄断私人诉讼的特殊需求,导致此类纠纷中私人利益和公共利益得不到有效的司法救济。借鉴域外经验,结合自身国情,构建我国反垄断私人诉讼原告资格制度至关重要。私人提起反垄断诉讼因其利益指向的不同有着反垄断私人诉讼之“公益诉讼”和“私益诉讼”的分化。在起诉者利益指向分化下,二者面临着截然不同的困境和需求,由此在原告资格的确立上也应有所差异,即反垄断私人诉讼适格原告二元化。     

储层岩石矿物成分对酸蚀裂缝导流能力的影响

储层岩石矿物成分是酸压改造效果影响因素之一。研究认为，在储层岩石矿物成分中易溶物的含量及分布方式决定了酸蚀裂缝导流能力大小，易溶蚀物的含量越多，岩石溶蚀速率越快。室内测试了不同溶蚀速率下的灰岩和白云岩的酸蚀裂缝导流能力，研究了岩石溶蚀速率、易溶蚀物含量对酸蚀裂缝导流能力的影响，对酸压工艺设计方案提出了指导性建议。研究结果表明，储层岩石溶蚀速率与酸蚀裂缝导流能力增加倍比存在抛物线关系，易溶蚀物占30%40% 时酸蚀裂缝导流能力保持较好。     

Uniform consistency rate of kNN regression estimation for functional time series data

In this paper, we investigate the k-nearest neighbours (kNN) estimation of nonparametric regression model for strong mixing functional time series data. More precisely, we establish the uniform almost complete convergence rate of the kNN estimator under some mild conditions. Furthermore, a simulation study and an empirical application to the real data analysis of sea surface temperature (SST) are carried out to illustrate the finite sample performances and the usefulness of the kNN approach.     

Toward an Application Guide for Safety Integrity Level Allocation in Railway Systems

The work in the article presents the development of an application guide based on feedback and comments stemming from various railway actors on their practices of SIL allocation to railway safety‐related functions. The initial generic methodology for SIL allocation has been updated to be applied to railway rolling stock safety‐related functions in order to solve the SIL concept application issues. Various actors dealing with railway SIL allocation problems are the intended target of the methodology; its principles will be summarized in this article with a focus on modifications and precisions made in order to establish a practical guide for railway safety authorities. The methodology is based on the flowchart formalism used in CSM (common safety method) European regulation. It starts with the use of quantitative safety requirements, particularly tolerable hazard rates (THR). THR apportioning rules are applied. On the one hand, the rules are related to classical logical combinations of safety‐related functions preventing hazard occurrence. On the other hand, to take into account technical conditions (last safety weak link, functional dependencies, technological complexity, etc.), specific rules implicitly used in existing practices are defined for readjusting some THR values. SIL allocation process based on apportioned and validated THR values is finally illustrated through the example of “emergency brake” subsystems. Some specific SIL allocation rules are also defined and illustrated.     

异质性技术视角下中国高技术制造业创新效率研究

目前，学术界对选取何种风险调整贴现率期限结构还存在争议，导致对同类投资项目得 出不同的管理指引意见． 针对这一争议，本文通过划分资本产出方式， 寻找影响贴现率结构的 主要因素． 研究表明，不确定的宏观经济产出和项目非系统风险共同影响风险溢价系数， 同时 风险溢价系数决定贴现率期限结构． 其中，当风险溢价系数大于某确定阈值， 贴现率随时间递 增; 其余情况表现为递减．     

Divorce and parity progression following the death of a child: A register-based study from Finland

Most studies that have examined whether a child’s death influences parental relationship stability have used small-scale data sets and their results are inconclusive. A likely reason is that child loss affects not only the risk of parental separation, but also the risk of having another child. Hence parity progression and separation must be treated as two competing events in relation to child loss. The analysis in this paper used Finnish register data from 1971 to 2003, covering over 100,000 married couples whose durations of both first marriage and parenthood could be observed. We ran parity-specific Cox regressions in which process time started from the birth of each additional child. All marriages included women of childbearing age, none of whom had experienced any child death on entering the analysis. We find that child loss only modestly influences the divorce risk, whereas its effect on the risk of parity progression is considerable.     

Explaining Italian “exceptionalism” and its end: Minimum income from neglect to hyper-politicization

Traditionally at the margins of the political debate, minimum income protection has recently become a key issue in Italian politics. After decades of social and political “neglect” letting Italy the only European country (with Greece) still lacking an anti-poverty minimum income safety net in the 2010s, finally a national programme called Inclusion Income was introduced in 2018, then replaced by a more robustly financed scheme, the Citizenship Income in 2019. The introduction of these new programmes was the object of an intense political debate, which raises two main puzzles. Why a policy field characterized by the low political resources of would be beneficiaries and low incidence on the overall welfare budget has become so important in the political debate? How did it occur in Italy, where minimum income protection had been absent in political discourses for at least five decades after World War II? To answer these questions, this article first elaborates a novel theoretical framework which combines the main properties of socio-political demand and political supply in order to explain the scope and direction of minimum income reforms. Second, it provides an analytically oriented reconstruction of MIS policy trajectory in Italy in the three different phases: the phase of MIS “neglect” (1948–1992) characterized by inertia; the period of political “contentiousness” (1993–2012), marked by attempts of path departure followed by policy reversals; the more recent phase leading to the introduction and institutionalization of a MIS. Third, the article provides a theoretically framed interpretation of the overall MIS trajectory in Italy.     

How do countries choose their monetary policy frameworks?

This paper investigates the determinants of countries’ choices of monetary policy framework. A brief narrative focused on groupings of countries motivates an econometric analysis which draws on previous work on the determinants of exchange rate regimes, bringing in standard factors as well as the trade networks of potential anchor currency blocs and the financial market depth that are emphasised in the narrative. The model turns out to be able to predict three quarters of countries’ choices, and there is no obvious systematic pattern in the errors. The results have important implications for how countries should choose their monetary policy frameworks.