Publications
The $$\gamma$$-metric value is generally used as the importance score of a feature (or a set of features) in a classification context. This study aimed to go further by creating a new methodology for multivariate feature selection for classification, whereby the $$\gamma$$-metric is associated with a specific search direction (and therefore a specific stopping criterion). As three search directions are used, we effectively created three distinct methods.
This study first time explores the impact of total factor productivity, renewable energy, exports, imports, and income on carbon emissions in the Gas Exporting Countries Forum (GECF) nations. To ensure that the results are sound and policy insights are well-grounded, three main issues of panel data – cross-sectional dependency, heterogeneity, and nonstationarity – are addressed using cutting-edge methods. Moreover, a theoretically justified framework is employed, offering advantages such as considering a broad set of factors, which are actionable from a climate policy perspective, with dual benefits of emissions reduction and supporting clean growth. We find that total factor productivity, renewable energy, and exports reduce carbon emissions, while income and imports have an increasing effect. Policymakers in GECF countries may consider implementing measures to support technological advancements, efficiency improvements, increased use of renewable energy, expanded exports, and lowered imports. They can reduce emissions while promoting sustainable economic growth.
This study investigates how El Niño–Southern Oscillation (ENSO) climate patterns affect global economic conditions. Prior research suggests that ENSO phases, particularly El Niño, influence economic outcomes, but with limited consensus on their broader macroeconomic impacts. Using a novel monthly dataset from 20 economies, covering 80% of global output from 1999 to 2022, we employ a global augmented vector autoregression with local projections (GAVARLP) model. The empirical findings suggest that El Niño boosts output with minimal inflationary effects, reducing global economic policy uncertainty, while La Niña raises food inflation, which can amplify aggregate inflation as a “second-round” effect, amplifying uncertainty. These findings shed light on the transmission channels of climate shocks and highlight the significant role of ENSO in shaping global economic conditions, emphasizing why climate shocks should be a concern for policy markers.
This paper studies the dynamics of information diffusion within networks, encompassing both general and targeted dissemination. We first characterize the theoretical foundations of diffusion centrality. Next, we introduce two extensions of diffusion centrality: targeting centrality and reachability, that we believe to better capture situations involving targeted requests. We derive general explicit formulas for the computation of these novel centrality measures.
This paper focuses on the welfare effects of domestic and international lobbying in the context of two countries linked by both trade and pollution. We consider a reciprocal-markets model where, in each country, a domestic firm produces a polluting good, that can result in a cross-national environmental externality, and competes in quantities in each market with a foreign firm. Each government independently sets a pollution tax under political pressure from green and industrial lobbies à la Grossman and Helpman (Am Econ Rev 84(4):833–850, 1994). Our results mainly show that political pressure from domestic and/or international lobbies can help mitigate tax competition between the two countries, resulting in an improvement in social welfare. In fact, lobbying acts much like a strategic delegation device by changing the social welfare weights in the objective function of each government. The (potential) welfare-improving effect of political pressure depends on the relative strengths of the lobbies and on the nature of the strategic interactions in taxes.
Under incomplete contracts, the mutual belief in reciprocity facilitates how traders create value through economic exchange. Creating such beliefs among strangers can be challenging even when they are allowed to communicate, because communication is cheap. In this paper, we first extend the literature showing that a truth-telling oath increases honesty to a sequential trust game with pre-play, fixed-form, and cheap-talk communication. Our results confirm that the oath creates more trust and cooperative behavior thanks to an improvement in communication; but we also show that the oath induces selection into communication — it makes people more wary of using communication, precisely because communication speaks louder under oath. We next designed additional treatments featuring mild and deterrent fines for deception to measure the monetary equivalent of the non-monetary incentives implemented by a truth-telling oath. We find that the oath is behaviorally equivalent to mild fines. The deterrent fine induces the highest level of cooperation. Altogether, these results confirm that allowing for interactions under oath within a trust game with communication creates significantly more economic value than the identical exchange institutions without the oath.
This paper considers a risk-neutral insurer and a risk-averse individual who bargain over the terms of an insurance contract. Under asymmetric Nash bargaining, we show that the Pareto-optimal insurance contract always contains a straight deductible under linear transaction costs and that the deductible disappears if and only if the deadweight cost is zero, regardless of the insurer's bargaining power. We further find that the optimality of no insurance is consistent across all market structures. When the insured's risk preference exhibits decreasing absolute risk aversion, the optimal deductible and the insurer's expected loss decrease in the degree of the insured's risk aversion and thus increase in the insured's initial wealth. In addition, the effect of increasing the insurer's bargaining power on the optimal deductible is equivalent to a pure effect of reducing the initial wealth of the insured. Our results suggest that the well-documented preference for low deductibles could be the result of insurance bargaining.
Based on a unique database (data on 2529 bank-firm relationships of 403 firms from 2012 to 2018) provided by the Central Bank of Tunisia, this article analyses the impact of the intensity and duration of bank-firm relationship on loan quality. By estimating a panel ordered probit model, the results show that the intensity of the lending relationship has a positive (negative) impact on high (medium or low) quality loans. In addition, the duration of the bank-firm relationship increases the probability of low-quality loans. We also find that the impact of relationship lending on loan quality differs according to the level of profitability of the firm. Low and non-performing firms tend to have longer and closer bank relationship, whereas it is the opposite for performing firms. Our results suggest that in an emerging market concentrated around a few banks, longer and closer banking relationships are mainly in favour of low and non-performing firms, reflecting adverse selection and strong moral hazard.
The Malthusian trap is a well recognized source of stagnation in per capita income prior to industrialization. However, previous studies have found mixed evidence about its exact strength. This article contributes to this ongoing debate by estimating the speed of convergence for a panel of 9 preindustrial European economies over a long period of time (14th–18th century). The analysis relies on a calibrated Malthusian model for England and β-convergence regressions. I find evidence of significant differences in the strength of the Malthusian trap between preindustrial European economies. The strongest estimated Malthusian trap is in Sweden, with a half-life of 20 years. The weakest estimated Malthusian trap is in England, with a half-life of about 230 years. This implies that some preindustrial economies were able to experience prolonged variations in their standards of living after a shock, while still being subject to Malthusian stagnation in the long run.
