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High-Order Hazard Functions and Treatment Choice
Get PDFHazard function applications in medical research are problematic for two reasons. First, they are not cast within a decision theory framework. Second, they often adopt severe self-imposed restrictive structures (e.g., in the constant hazard ratio models). The disadvantage of an excessively restrictive structure is self-evident. The disadvantage of the lack of a theoretical basis, which is more subtle, is that treatment choice itself becomes unnecessarily restrictive because decision theory insights remain untapped.
This paper uses a decision-theory-based framework for treatment choice, thus addressing the two issues above. It shows that high-order stochastic dominance tools, in conjunction with risk preference attributes, can often be used to compare treatments under weaker conditions than the ones currently used. The paper compares treatments by using what we call high-order hazard functions. These high-order hazard functions are obtained by calculating areas under low-order hazard functions (such as standard and cumulative hazard functions). The paper provides necessary and sufficient conditions for treatment comparisons based on these high-order hazard functions. These conditions are shown to be weaker than the ones currently used because we are able to exploit theoretical tools that are otherwise unavailable. Thus, for example, it shows that our framework often allows treatment comparisons even when hazard functions cross. An example using real-world data shows that the use of high-order stochastic dominance and risk preference attributes allows us to identify a preferred treatment even if low-order hazard functions cross
Identifying Optimal City Size by Considering Inverse U-Shaped Relationship Between Population and GDP
Get PDFIdentifying the optimal population size at which cities maximize economic benefits while minimizing congestion and pollution is a challenge. This research explores the optimal city size by examining the relationship between population and economic performance, measured by city GDP. Using data from OECD regions for about 562 cities, the analysis employs a quadratic regression model to test an inverse U-shaped relationship between city population and GDP in 2020. The empirical results show that cities initially experience economic growth as populations increase, but after a certain point (8.85 million), the benefits diminish due to congestion and pollution. The study concludes that an optimal city size exists, balancing the advantages of agglomeration with the costs of urban expansion. Additionally, population density, territorial fragmentation, working-age population, and built-up area positively affect city GDP, whereas air pollution negatively impacts it. Finally, several policies are recommended for sustainable urban development and efficient resource allocation
Granularity Shock: A Small Perturbation Two-Factor Model
Get PDFThe paper presents a small perturbation two-factor model designed to capture granularity risk, extending the Vasicek Asymptotic Single Risk Factor (ASRF) portfolio loss model. By applying the Lyapunov Central Limit Theorem, we demonstrate that, for small values of the Herfindahl-Hirschman Index (HHI), granularity risk, conditional on market risk, is proportional to a standard normal random variable. Instead of studying the behavior of a heterogeneous portfolio, we examine the behavior of a homogeneous portfolio subjected to a small perturbation induced by granularity risk. We introduce the Vasicek-Herfindahl portfolio loss distribution, which extends the Vasicek portfolio loss distribution for heterogeneous portfolios with low HHI values. Utilizing the Vasicek-Herfindahl distribution, we derive closed-form granularity adjustments for the probability density function and cumulative distribution function of portfolio loss, as well as for Value at Risk (VaR) and Expected Shortfall (ES). We compare the primary results of our approach with established findings and validate them through Monte Carlo simulations
Contractual and Governing Structures in Bulgarian Farming
Get PDFThere has been an unprecedented development in the governance of the supply of resources, services, innovations, and marketing of products of Bulgarian farms over the last two decades. However, due to insufficient (statistical, official, etc.) information and traditional inadequate (Neoclassical Economics, Agent Theory, etc.) approaches to analysis, there is no complete knowledge of the dominant forms and driving factors of governance in the main functional areas of farm management. This article incorporates the interdisciplinary New Institutional Economics framework and identifies the structure of governance and contractual modes used by Bulgarian farms. It is based on original and representative data collected through a survey with the managers of typical farms of different types and locations. The contemporary structure, factors and evolution of market, contract, internal, collective and hybrid modes of governance used by country's farms in the supply of natural, material, biological, financial and human resources, short-term assets, services, innovations, risk management, marketing of farm produce and services, and provision of ecosystem services, are all specified. A comparative study of the governance structures before the EU accession of the country is also made. The systemic application of the incorporated approach is needed, but it requires the collection of a new type of (micro)economic data on important characteristics of agricultural agents, different forms of governance of farm activities and relations, and critical dimensions and costs of transactions
Efectos no lineales del cambio climático y restricción de divisas en la inflación de alimentos
Get PDFThe present study analyzes the nonlinear effects of climate change and external constraints on food inflation in Bolivia, integrating astronomical (solar cycle), climatic (PDO, ENSO), and macroeconomic (foreign exchange scarcity index) factors using a quantile-conditional PVAR model. The findings indicate that, under conditions of elevated solar irradiance, the influences of the Pacific Decadal Oscillation and dollar scarcity on food prices are substantially amplified, resulting in increases reaching up to 10 percentage points. The interplay among extreme climate shocks (El Niño, La Niña), production stress, and exchange rate restrictions gives rise to a composite vulnerability architecture that transcends linear analytical frameworks. It is recommended that climate and astronomical variables be integrated into forecasting models, that food reserves be strengthened, that indexed climate insurance be developed, and that differential exchange rate policies be adopted for strategic sectors. The study offers pertinent empirical and methodological evidence to anticipate risk scenarios and design more resilient multi-scale responses
Towards an ethical consensus for sustainable development: the role of values, morals, and norms in shaping pro-environmental behaviour
Get PDFThe aim of the review is to investigate the critical role of psychological and sociocultural factors in sustainable development. Unlike traditional approaches that prioritize mainly on technical and economic solutions, the novelty of this work lies in its reframing of sustainability through a deeply social and ethical lens. The paper introduces a multidimensional perspective on sustainable transformation through an extensive synthesis of behavioural theories, climatic-oriented psychological elements (e.g., eco-anxiety), and cultural practices (e.g., biomimicry). The three review’s objectives are to: (i) incorporate psychological and sociocultural dimensions into sustainable development agenda; (ii) demonstrate how values, norms, and perceptions shape pro-environmental behaviours; and (iii) call for an ethical consensus across societal sectors. Essentially, this integrative approach seeks to build more inclusive, resilient, and ethically grounded pathways to sustainable development, as sustainable development is not only a techno-economic challenge,but also a deeply socio-ethical endeavour
Impact of legislation on gig workers: evidence from Chile
Get PDFBased on representative samples of gig workers from Chile (drivers and riders working through applications like Uber and Rappi), this paper explores the subjective and objective impact of two Chilean laws regarding the gig economy. The demographic and employment characteristics of these workers, including job satisfaction and motivation, are also analyzed. Overall, laws have a muted to negative effect on workers. For the first law (which formalizes the status of gig workers as workers), those who report a negative impact associate it with less flexibility regarding working hours, in addition to the now compulsory income taxes. For the second law (which increases the requirements to work as driver), more than half report that they will stop working. Partial compliance with the law also stands out, which is particularly clear in the low and stable rate of income reporting to the State by workers
Can Remittances Drive Inclusive Human Development in Sub-Saharan Africa?
Get PDFThis paper analyses the effect of remittances on inclusive human development in sub-Saharan Africa. It considers the conditional effects of ICT, dual nationality, and financial development within this relationship. Estimates were derived using Population-Averaged Generalised Estimating Equations (PA-GEE), Fixed Effects Instrumental Variable (FEIV), and Method of Moments-Quantile Regression (MM-QR) on a panel of 31 countries over the period 2010–2017. The findings indicate that remittances positively contribute to inclusive human development. The interaction between remittances, financial development, and ICT further enhances this impact, as does dual citizenship. These results are robust and suggest that ICT through collaboration between migrants and their country of origin, laws favouring multiple citizenship, an efficient financial system and a business-friendly institutional environment, optimises the effect of remittances on inclusive development in sub-Saharan Africa
The country ICT level and the Fintech firm Performance: Evidence from BRICS Countries
Get PDFPurpose
The scope of this paper is to investigate if the information and communications technology (ICT) can improve the FinTech firm performance in the BRICS countries from monthly macro time series data during 2014M01-2022M12.
Design/methodology/approach
Through the Bayesian VAR-X approach and the time series DYNARDL simulation models, we investigate the impact of the ICT and its components on the firm performance for both the short-run (SR) and the long-run (LR) historical and predictive trend. Besides these regression models, this study applies the Granger Causality (GC) in quantile and the frequency domain (FD) GC tests to show more details about the causality linkage.
Findings
From the BVAR-X approach, historical IRFs conclude that the ICT has positive effect on PI for all countries in the SR and a positive effect in the LR only for China. From the DYNARDL simulation models, predictive IRFs results corroborate with the historical IRFs results except for the China and SA in the SR and for Brazil and India in the LR. We conclude in addition that the predictive positive relationships is driven by MCS for Brazil, IUI for China, FBS for SA, and all of the ICT components for the India case. GC type test results are in accordance with previous results.
Originality
The novelty of this research is based on the idea of studying the effect of the ICT on FinTech firm performance by using several time series data based dynamic technics so that we can estimate and predict the SR adjustments that arise from the impact of ICT to the LR relationship with the firm profitability.
Unilateral decisions to hire managers in a mixed duopoly with a foreign labour-managed competitor
Get PDFNumerous studies examine the strategic decisions regarding managerial incentive contracts within private oligopoly markets. Several studies also delve into managerial incentives within mixed oligopoly markets, where state-owned public firms with economic welfare objectives compete against capitalist private firms focused on profit objectives. Additionally, several recent studies consider international mixed oligopoly markets with foreign capitalist firms. For example, one study examines the decisions of firms to hire managers when a state-owned public firm competes with a foreign capitalist firm, indicating that in equilibrium, both firms hire managers, leading to higher domestic economic welfare compared to a scenario where neither firm hires a manager. However, these studies typically focus on mixed oligopoly markets where state-owned firms compete with capitalist firms and do not consider the presence of labour-managed firms. In this paper, we investigate the firms’ decisions to hire managers when a state-owned firm competes with a foreign labour-managed firm. We reveal that our equilibrium outcomes coincide with the equilibrium where neither firm hires a manager