A critical overview of privacy-preserving approaches for collaborative forecasting

Cooperation between different data owners may lead to an improvement in forecast quality—for instance, by benefiting from spatiotemporal dependencies in geographically distributed time series. Due to business competitive factors and personal data protection concerns, however, said data owners might be unwilling to share their data. Interest in collaborative privacy-preserving forecasting is thus increasing. This paper analyzes the state-of-the-art and unveils several shortcomings of existing methods in guaranteeing data privacy when employing vector autoregressive models. The methods are divided into three groups: data transformation, secure multi-party computations, and decomposition methods. The analysis shows that state-of-the-art techniques have limitations in preserving data privacy, such as (i) the necessary trade-off between privacy and forecasting accuracy, empirically evaluated through simulations and real-world experiments based on solar data; and (ii) iterative model fitting processes, which reveal data after a number of iterations.     

The Effect of Explicit Communication on pricing: Evidence from the Collapse of a Gasoline Cartel

We study the collapse of collusion in Québec's retail gasoline market following a Competition Bureau investigation, and show that it involved two empirical regularities: high margins, and asymmetric price adjustments. Using weekly, station‐level prices we test whether collusion was successful, and whether asymmetric adjustments were part of the cartel's strategy. We do so in the markets targeted by the investigation, and in markets throughout the province with similar pre‐collapse pricing (cyclical markets). Our results suggest that stations in both target and cyclical markets adjusted pricing following the announcement: margins fell (by 30%/15% in target/cyclical markets), and adjustments became more symmetric.     

Healthcare costs of stroke and major bleeding in patients with atrial fibrillation treated with non-vitamin K antagonist oral anticoagulants

Objective: To assess long-term healthcare costs related to ischemic stroke and systemic embolism (stroke/SE) and major bleeding (MB) events in patients with non-valvular atrial fibrillation (NVAF) treated with non-vitamin K antagonist oral anticoagulants (NOACs).

Materials and methods: Optum’s Clinformatics Data Mart database from 1/2009–12/2016 was analyzed. Adult patients with ≥1 stroke/SE hospitalization (index date) were matched 1:1 to patients without stroke/SE (random index date), based on propensity scores. Patients with an MB event were matched to patients without MB. All patients had an NOAC dispensing overlapping index date, ≥12?months of eligibility pre-index date, and ≥1 NVAF diagnosis. The observation period spanned from the index date until the earliest date of death, switch to warfarin, end of insurance coverage, or end of data availability. Mean costs were evaluated: (1) per-patient-per-year (PPPY) and (2) at 1, 2, 3, and 4?years using Lin's method.

Results: The cost differences were, respectively, $48,807 and $28,298 PPPY for NOAC users with stroke/SE (n?=?1,340) and those with MB (n?=?3,774) events compared to controls. Cost differences of patients with vs without stroke/SE were $49,876, $51,627, $57,822, and $60,691 at 1, 2, 3, and 4?years post-index, respectively (p?p?Limitations: Limitations include unobserved confounders, coding and/or billing inaccuracies, limited sample sizes over longer follow-up, and the under-reporting of mortality for deaths occurring after 2011.

Conclusions: The incremental healthcare costs incurred by patients with vs without stroke/SE was nearly twice as high as those of patients with vs without MB. Moreover, each additional year up to 4?years after the first event was associated with an incremental cost for patients with a stroke/SE or MB event compared to those without an event.     

Gender and ethnic earnings gaps in seven West African cities

In this paper, we measure, compare and analyse gender and ethnic earnings gaps in seven West African capitals using data from an original series of urban household surveys. Our results show that gender earnings gaps are large in all the cities in our sample with significant variations across cities. Cities with large gender earnings gaps are also where gender education gaps are wider and where the female labour market participation is highest. Decomposition of the gender gaps shows that differences in characteristics explain around 40% of the raw gender gap on average, but this varies somewhat across cities. The results of the full decomposition of the gender earnings gaps suggest that differences in sector allocation contribute, on average, to one third of gender earnings gaps. Gender gaps are very wide in the informal sector and differences in micro-firm characteristics also account for differences in self-employment earnings. In contrast to the large gender earnings gaps measured in the seven cities, majority ethnic groups do not appear to be in a systematically advantageous position on the urban labour markets in our sample of cities, and observed gaps are small compared with gender gaps. Looking at more detailed levels of ethnic disaggregation, ethnic earnings differentials are found to be systematically smaller than gender differentials. Moreover, none of the minority “favoured” groups seem to have any relation to the ethnicity of the Head of State at the time of the survey. Holding productive characteristics constant, some unexplained differences persist however.     

A Tutorial on Palm Distributions for Spatial Point Processes

This tutorial provides an introduction to Palm distributions for spatial point processes. Initially, in the context of finite point processes, we give an explicit definition of Palm distributions in terms of their density functions. Then we review Palm distributions in the general case. Finally, we discuss some examples of Palm distributions for specific models and some applications.     

Banks and Microbanks

We combine two datasets to examine whether the presence of banks affects the profitability and outreach of microfinance institutions. We find evidence that competition matters. Greater bank penetration in the overall economy is associated with microbanks pushing toward poorer markets, as reflected in smaller average loans sizes and greater outreach to women. The evidence is particularly strong for microbanks relying on commercial-funding and using traditional bilateral lending contracts (rather than group lending methods favored by microfinance NGOs). We consider plausible alternative explanations for the correlations, including relationships that run through the nature of the regulatory environment and the structure of the banking environment, but we fail to find strong support for these alternative hypotheses.     

Revisiting the finance–growth nexus: the Turkish case, 1980–2010

In Turkey, the empirical results on the link between financial development and economic growth are mixed. The existing studies do not take into account the fact that Turkey has experienced endemic political and economic instabilities over extended periods. This study aims to analyse the role of macroeconomic instability and public borrowing on the finance–growth nexus in Turkey by using time series econometric techniques over the 1980–2010 period. In doing so, we attempt to extend the existing literature by taking into account the role of macroeconomic instability as well as public borrowing. Our results reveal that there are additional – albeit indirect – channels between finance and growth via the effects of macro instability and public borrowing on financial development and economic growth. After taking into account the effects of overall instability and public borrowing, we found that growth–financial development relationship is bidirectional and permanent. In other words, in Turkish case, economic growth and financial development are jointly determined. Thus, our results shed some light on the ambiguity of the evidence on the link between financial development and economic growth for Turkey.     

How resilient is La Réunion in terms of international tourism attractiveness: an assessment from unit root tests with structural breaks from 1981-2015

Even if local policymakers increasingly claim that tourism is one of the key factors of future economic development for the French small island La Réunion, international tourist arrivals are observed to be locked in a stagnation phase since the beginning of the 2000s. Starting from this stylized fact, this article aims to study if this phenomenon results from major external events hurting this economy regularly. Next, by using univariate unit root procedures with structural breaks, we test for evidence of permanent or transitory effects of external shocks on international tourist inflows (total, by source markets, and by category) over the period 1981–2015. Finally, the empirical analysis allows us to reject the null of a unit root. Then, stagnation of tourism arrivals to La Réunion is not due to exogenous shocks but probably results from endogenous impediments within the domestic tourism industry and unsuitable public policies.     

The risk-based approach under the new EU data protection regulation: a critical perspective

Abstract

The first broad reform of personal data protection legislation in the European Union entered into force in May 2018 (Regulation (EU) 2016/679, the General Data Protection Regulation). Remarkably, with this reform a risk-based approach has been introduced as the core data protection enforcement model, while data protection authorities see their regulatory role significantly weakened. The risk-based approach is to be implemented by the data controllers (i.e. the operators) via data protection impact assessments (evoking the established environmental impact assessment procedure) and notification of breaches, among other procedures. Hence the scope of both the concepts of risk and risk regulation spread beyond conventional domains, namely the environment, public health or safety, i.e. physical risks, to encompass risks to intangible values, i.e. individual rights and freedoms, presumably harder to assess and manage. Strikingly, the reform has been accompanied by a confident discourse by EU institutions, and their avowed belief in the reform’s ability to safeguard the fundamental right to data protection in the face of evolving data processing techniques, specifically, big data, the Internet of Things, and related algorithmic decision-making. However, one may wonder whether there isn’t cause for concern in view of the way the risk-based approach has been designed in the data protection legislation. In this article, the risk-based approach to data protection is analysed in the light of the reform’s underlying rationality. Comparison with the risk regulatory experience in environmental law, particularly the environmental impact assessment procedure, is drawn upon to assist us in pondering the shortcomings, as well as the opportunities of the novel risk-based approach.