Concave Relationship Research Articles

Variance of deviation from optimal leverage

AbstractWe show that deviations from the firm's target leverage are priced in the cross‐section of stock returns and that the relation between these quantities is nonlinear. The concave nonlinear relation between deviation from the target leverage and next‐period return is strong during economic expansions and vanishes during recessions. Our portfolio analysis provides support for the concave relation between deviation from the target leverage and next‐period returns as well. We develop a factor named variance of deviation from optimal leverage (VDOL) and show that it is an important risk factor that has been omitted in the literature.

Predicting hostility towards women: incel-related factors in a general sample of men.

Hostility towards women is a type of prejudice that can have adverse effects on women and society, but research on predictors of men's hostility towards women is limited. The present study primarily introduced predictors associated with misogynist involuntary celibates (incels), and then investigated whether loneliness, rejection, attractiveness, number of romantic and sexual partners, right-wing authoritarianism, and gaming predicted hostility towards women among a more general sample of men. A total of 473 men (aged 18-35, single, heterosexual, UK residents) recruited via Prolific answered the hostile sexism subscale, the misogyny scale, the self-perceived sexual attractiveness scale, the right-wing authoritarianism scale, the game addiction scale for adolescents, the adult rejection-sensitivity scale, the UCLA loneliness scale, and self-developed questions regarding number of sexual and romantic partners, and time spent gaming. We found a strong positive relationship between right-wing authoritarianism and hostility towards women, as well as a strong convex curvilinear relationship between attractiveness and hostility towards women. The number of sexual partners showed a moderate concave relationship with hostility towards women. We did not find sufficient support for a relationship between gaming and hostility towards women, and there was no support that loneliness, rejection, or romantic partners predicted hostility towards women among a general sample of men. Our study supports right-wing authoritarianism and self-perceived attractiveness as potential strong predictors in understanding men's hostility towards women in the wider community. Pre-registration: https://osf.io/ms3a4.

Optimizing information-driven awareness allocation for controlling activity-triggered epidemic spread

In the contemporary era, the advent of epidemics instigates a substantial upswing in relevant information dissemination, bolstering individuals’ resistance to infection by concurrently reducing activity contacts and reinforcing personal protective measures. To elucidate this intricate dynamics, we introduce a composite four-layer network model designed to capture the interplay among information-driven awareness, human activity, and epidemic spread, with a focus on the allocation of individuals’ limited attention in diminishing activity frequency and self-infection rates. One intriguing observation from our findings is an anomalous, concave non-monotonic relationship between awareness trade-off and epidemic spread, with a more pronounced prevalence at an intermediate least awareness efficacy. This underscores the inadvisability of relaxing self-protection through reduced activity frequency or compensating for increased activity frequency by enhancing self-protection. Especially noteworthy is the significance of enhancing self-protection in response to heightened information dissemination and inherent activity demands to curtail infection risk. However, in scenarios with increasing ancillary activity frequency, the emphasis should exclusively shift towards reducing activity exposure. The model establishes a theoretical threshold for accurately predicting awareness efficacy in epidemic outbreaks. Optimal awareness allocation consistently resides at the extremes—either completely avoiding unnecessary activity contact or adopting full self-protection. This guidance, contingent on information level and activity demand, offers valuable insights into the delicate balance between individual behaviors and epidemic prevention.

Analysis of driving behavior in weak lane disciplined traffic at the merging and diverging sections using unmanned aerial vehicle data

The complexity of vehicular interactions at the merging and diverging sections is more severe due to the multiple decisions the driver has to make in a short time. The present study investigates and quantifies the driving behavior at the toll plaza’s merging and diverging sections. High-quality trajectory data for more than 7500 vehicle trajectories was derived from traffic video footage recorded by two Unmanned Aerial Vehicles (UAVs) operating concurrently upstream and downstream of the toll plaza. The data was extracted at 5 Hz, generating more than 5 million data points for the study. This approach facilitated a comprehensive and simultaneous capture of traffic dynamics. Various macroscopic and microscopic traffic parameters, like lateral and longitudinal speeds, following time, perception time, longitudinal standstill distance, and lateral clearance in the upstream and downstream sections, have been determined under weak lane disciplined traffic conditions. The mean speed in the merging section is 33.13 % lower than in the diverging section. Additionally, the average lateral speed in the merging section is 1.65 km/h, in contrast to 2.08 km/h in the diverging section, reflecting a 26 % increase. The lane changing and merging is prominent only up to 120 m to 140 m from the toll plaza in the merging section, and for diverging, 100 m to 200 m towards the toll plaza. The average following time in the diverging section is 5.7 s; for the merging section, it is 6.94 s, which is 13.86 % higher. The average perception time for the diverging section is 15.32 s; for the merging section, it is 13.13 s, which is 14.29 % lower. It has been observed that lateral clearance has a concave relationship with the speed in the merging section, whereas a convex relationship is in the diverging section due to the geometrical changes. The results presented in the study are expected to imitate heterogeneous traffic conditions observed in the field more realistically and will accelerate the understanding of behavioral aspects in complex interactive environments like that at merging and diverging sections of toll plazas.

Optimal carrying capacity in rural tourism: Crowding, quality deterioration, and productive inefficiency

This paper introduces a novel framework for characterizing destination overcrowding in rural tourism using a production approach. We build upon destination life cycle, carrying capacity, and consumer preference theories to characterize optimal levels of overnight stays in the presence of disutility from crowding. Using panel data for rural tourism in Spanish provinces, we model crowding non-linearly as a demand shifter within a service production function. To deal with plausible endogeneity, we use a control function approach within a Stochastic Frontier regression. Consistent with our theoretical predictions, we show there is a non-linear concave relationship between overnight stays and crowding. We calculate optimal carrying capacity levels (turning points) for each province and illustrate which regions are exhibiting negative externalities from overcrowding.

Online learning of order flow and market impact with Bayesian change-point detection methods

Financial order flow exhibits a remarkable level of persistence, wherein buy (sell) trades are often followed by subsequent buy (sell) trades over extended periods. This persistence can be attributed to the division and gradual execution of large orders. Consequently, distinct order flow regimes might emerge, which can be identified through suitable time series models applied to market data. In this paper, we propose the use of Bayesian online change-point detection (BOCPD) methods to identify regime shifts in real-time and enable online predictions of order flow and market impact. To enhance the effectiveness of our approach, we have developed a novel BOCPD method using a score-driven approach. This method accommodates temporal correlations and time-varying parameters within each regime. Through empirical application to NASDAQ data, we have found that: (i) Our newly proposed model demonstrates superior out-of-sample predictive performance compared to existing models that assume i.i.d. behavior within each regime; (ii) When examining the residuals, our model demonstrates good specification in terms of both distributional assumptions and temporal correlations; (iii) Within a given regime, the price dynamics exhibit a concave relationship with respect to time and volume, mirroring the characteristics of actual large orders; (iv) By incorporating regime information, our model produces more accurate online predictions of order flow and market impact compared to models that do not consider regimes.

Spatial Heterogeneity in Determinants of No Condom Use at First Sex in South Africa

Background Condom use, especially at first sex for unmarried people, is an important behaviour that reduces the risk of HIV transmission, and other Sexually Transmitted Diseases (STDs), as well as unwanted pregnancies. In reviewing the literature, little information was found to elucidate the spatial context of condom use among people who had an early sexual debut. Understanding factors that influence no condom use at first sex in different local or geographical areas can add value in addressing these risky first-sex practices and minimise the risk of getting HIV, STDs, and unwanted pregnancies in South Africa, especially among young people. Therefore, this paper aimed to determine the spatial heterogeneity of factors associated with no condom use at first sex in South Africa using Geographically Weighted Regression (GWR) with Poisson distribution and local bivariate relationships. Methods This article used data from the fifth South African National HIV Prevalence, HIV Incidence, Behaviour and Communication Survey (SABSSM V) of 2017. Spatial autocorrelation, GWR using Poisson distribution, and local bivariate relationships were undertaken using ArcGIS Pro. Results Geographically weighted regression using Poisson distribution results highlighted being female, being young, having never married, being unemployed, having sexual debut at a younger age, having two or more sexual partners, having no risk of being infected with HIV, and having good Self-perceived Health (SPH) to be significant factors influencing no condom use at first sex, with pseudo R2 = 0.96 and AICc = 692. Local bivariate relationships showed the relationship between no condom use at first sex and most explanatory variables to exhibit a positive linear relationship in most districts with the exception of having never married, which showed a positive linear relationship in only 18 districts, while 33 districts showed a concave relationship. These relationships were all significant with p < 0.05. Conclusion This localised analytical approach may contribute to the development of geo-targeted interventions and policies tailored to specific regions within South Africa, thereby improving the effectiveness of efforts to promote safe first sexual practices. Educational programs targeting youth should be developed to further raise awareness of the risks associated with unprotected sex and the importance of condom use. More efforts should be made to break the barriers, such as sexual relationship power, gender, and sociocultural and religious influences, which tend to put young, never-married, and unemployed women at risk of no condom use at first sexual debut. It is further recommended that the type of relationship between no condom use at first sex and each explanatory factor at the local region be considered during geo-targeted interventions as this will assist in the type of intervention and duration of intervention.

More knowledge, better innovation? Role of knowledge breadth and depth

PurposeCurrent open innovation (OI) and external knowledge search (EKS) research primarily shows a positive linear relationship between EKS and innovation at an individual level. However, organizational scholarship argues that excessive EKS may harm innovation. This study combines the knowledge-based view (KBV) and attention-based view (ABV) to articulate a nonlinear theory of EKS and innovation at the individual level.Design/methodology/approachThe authors constructed a multi-sourced dataset covering 59,798 USA pharmaceutical patents spanning from 1975 to 2014 and employed negative binomial fixed-effect models to examine theoretical hypotheses.FindingsWe find a significant concave curvilinear relationship between EKS and innovation quantity as well as innovation quality at an individual level. An individual’s knowledge breadth and depth moderate the relationship between EKS and innovation, such that the threshold at which EKS has diminishing returns for individual innovation is higher for inventors with a broad range of knowledge and those with deeper expertise in the domain where they are innovating.Research limitations/implicationsManagers should guide inventors toward a moderate investment of time and effort in EKS and should caution against over searching. Besides, managers should recognize that an inventor’s capacity for EKS is determined in part by their breadth of knowledge across various domains as well as the depth of knowledge they have in the knowledge domain where they are innovating.Practical implicationsWe provide both parties with a clearer understanding of when EKS can begin to deteriorate an individual’s innovation performance why that deterioration occurs, and we also highlight two individual-level knowledge characteristics to take into consideration when deciding when to cease the EKS process.Social implicationsThis study provides a novel holistic understanding of OI and knowledge management for policymakers and organizations to nourish innovation dynamism and make the best of knowledge stocks in the community, which in turn will create endless power for sustainable social change and inclusive development.Originality/valueThis study contributes to OI theory by highlighting the non-linear nature of the relationship between EKS and innovation on an individual level. This represents a fundamental shift in theory on EKS and individual innovation by suggesting a major rethinking of how the two concepts relate, revealing the dark side of EKS in knowledge management if inventors engage in excessive EKS. Likewise, our study’s incorporation of the ABV informs KBV scholarship by highlighting the role of the limited attentional capacity of individuals in firm knowledge management.

The impact of working capital on the profitability and liquidity risk of Greek companies

The main purpose of this paper is to investigate whether working capital management (WCM) has a significant impact on the profitability of small and medium-sized enterprises (SMEs). This study intends to contribute to the existing literature by examining further whether there is a linear and a no-linear relationship (concave) between WCM and the profitability of Greek SMEs and by focusing on the economic crisis period that has a significant effect on the financial data of the Greek SMEs. The sample consists of 101 Greek SMEs from various industries (e.g., consumer goods, industrials, and healthcare) for the period between 2014 and 2020. The results led to the conclusion that the fixed effects model was appropriate for our data. Regarding the utilized indicators, the cash conversion cycle (CCC) is used as a proper indicator for the WCM while return on asset (ROA), return on equity (ROE), and return on capital employed (ROCE) are considered for profitability. Furthermore, this paper innovates, since each working capital factor was examined separately to identify to what extent they can affect profitability indicators on a stand-alone basis. According to the empirical results considering ROA there exists a concave relationship between profitability and WCM.

Bonds with Benefits: Impact Investing in Corporate Debt

The regulatory focus on quantifiable sustainable investing shifts investors’ demand toward impact products, which creates challenges in achieving their primary target of outperformance. This study demonstrates the implications of sustainable investment in actively managed credit portfolios using carbon emissions, Sustainable Development Goals (SDGs), and green bonds. All three measures exhibit a low correlation with systematic factors, such as value and momentum, providing an opportunity for a sustainable alpha. Furthermore, we demonstrate a concave relationship between outperformance and sustainability. Therefore, systematic investors achieve a sustainable portfolio at a low cost, whereas sustainability-oriented investors harness factor returns and meet their initial targets.

Interactions between monovalent cations and polyethylene glycol: A study at micro level

Understanding the intricate interplay between ions and polymers holds key implications for a myriad of fields, from biomedicine to materials science. Here, we present a comprehensive investigation of ion-specific effects on the behavior of single polyethylene glycol (PEG) chains, a versatile polymer widely used in various applications. Employing single-molecule force spectroscopy (SMFS) and quartz crystal microbalance with dissipation (QCM-D) techniques, we systematically explore the impact of different monovalent cations on structural and hydration dynamics of PEG, Surprisingly, our results demonstrate a non-linear ion-specific influence on the hydration of PEG chains. The introduction of ions significantly affects the binding water content and the single-chain elastic behavior of PEG. Intriguingly, monovalent cations display an intriguing concave relationship between their size and the extent of water binding. Li+ and Na+, characterized by their smaller size and higher charge density, induce pronounced hydration, thus altering the overall structural properties of PEG chains. In contrast, larger cations like Rb+ and Cs+ facilitate chain extension, while concurrently promoting the formation of binding water. Our findings offer a fresh perspective on the role of ion size and charge density in governing polymer-water interactions. Moreover, through quantitative analysis utilizing QCM data, we verify the intricate influence of ions on PEG chains. Our research contributes to unraveling the complex interplay between ions and polymers, highlighting the importance of ion-specific effects in shaping polymer behavior. While shedding light on the potential of polymer materials with tailored properties, it also underscores the need for further investigations into the mechanisms underlying ion-specific effects and their broader implications.

Impact of cementitious materials on the resilient modulus and damping ratio of weak subgrade

Pavement structures are constantly subjected to cyclic loadings. The resilient modulus and damping ratio are frequently used to evaluate the stress–strain relationships and energy dissipation for pavement subbase and subgrade. This paper presents an experimental study on the resilient modulus characterization, and damping ratio calculation for hydraulic road binder (HRB) treated weak subgrade soils. Results indicated that similar to General Use (GU) cement, HRB significantly enhanced the soil’s resilient modulus by increasing internal structural stability in cementitious treated soils. Using current stress-dominated constitutive models, a fair prediction can be achieved for GU- and HRB-treated soils, especially for lower MR values (<500 MPa). In addition, there is a concave downwards relationship between the damping ratio, total axial stress, and resilient modulus, respectively. Under repeated loading, higher energy dissipation for treated soils is anticipated within a certain range of axial stress levels.Furthermore, the mean resilient modulus of GU- and HRB-treated soils highly correlated with moisture content and with the actual content of cementitious materials: cement clinker and ground-granulated blast-furnace slag (GGBFS) in the treated soils. Their contributions could be further quantified by efficiency factors. Overall, the outcomes of this study could be a reference for the future investigation and development of hydraulic road binders and contribute to the future substitute of conventional Portland cement in pavement engineering.

Football Players With Hip Dysplasia: The Relationship Between Muscle Strength, Functional Performance, Self-reported Sport and Recreation, Cartilage Defects, and Sex. A Cross-sectional Study.

OBJECTIVE: In symptomatic football players with hip dysplasia, we aimed to explore the relationships between self-reported sport and recreation ability and (1) hip muscle strength, (2) functional performance, and investigate if these relationships were modified by sex or cartilage defects. METHODS: In this cross-sectional study, football players (n = 50) with longstanding (>6 months) hip and/or groin pain, a positive flexion/adduction/internal rotation test, and a lateral-center-edge angle <25° were included. Hip muscle strength and functional performance were assessed. Self-reported sport and recreation ability was quantified using the sports and recreational subscales from the International Hip Outcome Tool-33 (iHOT-Sport) and the Copenhagen Hip and Groin Outcome Score (HAGOS-Sport). Relationships were evaluated using regression models with sex and cartilage defects as potential effect modifiers. RESULTS: There was a positive linear relationship between the one-leg-rise test and the iHOT-Sport subscale (β = 0.61; 95% CI: 0.09, 1.14). A polynomial (concave) relationship was found between peak eccentric adduction strength and the HAGOS-Sport subscale (β = -30.88; 95% CI: -57.78, -3.99). Cartilage defects modified the relationship between peak isometric adduction strength and HAGOS-Sport, with those with cartilage defects having a polynomial (convex) relationship (β = 36.59; 95% CI: 12.74, 60.45), and those without cartilage defects having no relationship. CONCLUSION: One-leg-rise performance and adduction strength were associated with self-reported sport and recreation ability, indicating a possible relationship between physical function, hip joint structure, and sport and recreation ability in football players with hip dysplasia. J Orthop Sports Phys Ther 2023;53(10):1-8. Epub: 8 September 2023. doi:10.2519/jospt.2023.12026.

Role of Disciplinary Tools in Maintaining Bank Performance and Financial Stability: Evidence from Emerging Economies

The aim of this study is to examine the role of disciplinary tools, that is, capital adequacy requirement and market discipline in maintaining the banks’ performance and financial stability. The study employs a panel dataset of 600 commercial banks from BRICS economies for the period ranging from 2005 to 2020 using the panel regression. The robustness of the results is validated using the system GMM (generalized method of moments). The study reveals that, in a linear model, capital adequacy ratio has a positive influence on performance and stability, and market discipline has a negative influence on performance and stability. In a non-linear model, capital adequacy ratio has a concave relationship. Further, the study discusses the critical determinants of profitability and stability. JEL Classification: G21, G28, G32

The genotype–phenotype relationship and evolutionary genetics in the light of the Metabolic Control Analysis

Metabolic control analysis has long been used as a systemic model of the genotype–phenotype (GP) relationship. By considering kinetic parameters and enzyme concentrations as reflecting the genotype level and metabolic fluxes or pools as phenotypes related to fitness, MCA has given a biological basis to the relationship between these two levels. The non-linear and concave relationship between enzymes and fluxes can account for common genetic effects that reductionist approaches have been powerless to explain, such as the dominance of active alleles over less active alleles, the various types of epistasis and heterosis, and reveals the structural links between these genetic effects. The summation property of the flux control coefficients accounts for the L-shaped distribution of Quantitative Trait Locus (QTL) effects, irrespective of other possible causes. Metabolic models of response to selection results in evolutionary scenarios that are markedly different from those derived from the classical infinitesimal model of quantitative genetics. In particular, evolution towards selective neutrality appears to be a consequence of the diminishing return of the flux-enzyme relationship. In this paper, we survey the historical and recent achievements of MCA in genetics, quantitative genetics and evolution, focusing on epistasis and the evolution of flux in relation to enzyme concentrations.

Do board gender diversity and remuneration impact earnings quality? Evidence from Spanish firms

PurposeThis study aims to investigate how gender diversity and remuneration of boards of directors’ influence earnings quality for Spanish-listed firms.Design/methodology/approachThe sample includes 105 nonfinancial Spanish firms from 2013 to 2018, corresponding to an unbalanced panel of 491 firm-year observations. The primary empirical method uses a Tobit semiparametric estimator with firm- and industry-level fixed effects and an innovative set of measures for earnings quality developed by StarMine.FindingsResults exhibit a positive correlation between increased gender diversity and a firm’s earnings quality, suggesting that a gender-balanced board of directors is associated with more transparent financial reporting and informative earnings. We also find a nonmonotonic, concave relationship between board remuneration and earnings quality. This indicates that beyond a certain point, excessive board compensation leads to more opportunistic manipulation of financial reporting with subsequent degradation of earnings quality.Research limitations/implicationsThis study only covers nonfinancial Spanish listed firms and is silent about how alternative board features’ influence earnings quality and their informativeness.Originality/valueThis study introduces measures of earnings quality developed by StarMine that have not been used in the empirical literature before as well as measures of board gender diversity applied to a suitable Tobit semiparametric estimator for fixed effects that improves the precision of results. In addition, while most of the literature focuses on Anglo-Saxon countries, this study discusses board gender diversity and board remuneration in the underexplored context of Spain. Moreover, the hand-collected data set comprising financial reports provides previously untested board features as well as a nonlinear relationship between remuneration and earnings quality that has not been thoroughly discussed before.

The challenges of using ranks to estimate sales

AbstractResearchers have frequently used data on product ranks to estimate nonpublic sales quantities, believing that there is a power‐law‐induced linear relationship between logged sales ranks and logged sales. Using essentially complete data on book sales, the most commonly used product in this literature, we find that the (double‐logged) relationship between sales ranks and quantity sold is not linear, but robustly concave. We demonstrate that this concavity is likely to cause very poor sales predictions in many instances. We provide two concrete examples where applying this linear method to the concave relationship has led to serious errors in sales estimates. First, in the claim that the Internet's greater product variety in books has a large positive impact on social welfare, and second, in a claim about relative sales levels in top 20 and top 50 music “charts.” We also explore the use of nonlinear specifications as an alternative method to predict sales from ranks and find a simple specification that provides much better sales estimates. Finally, we examine the possibility that a particular type of biased sample might allow reasonable linear estimates of industry sales and conclude that it is possible but quite unlikely.

Effect of time stress and store visibility on the dynamics of passenger activity choices at airport terminals based on indoor trajectory data

As mobile devices become more sophisticated and ubiquitous, airports have greater access to information on the activities of passengers and their reasons for engaging in such activities. This study proposes a novel trajectory-based dynamic choice model that can capture the effects of time stress, store visibility, and trajectory histories on activity choices in airport terminals. To evaluate the proposed model, two surveys on passenger trajectories and activities at Songshan Airport in Taipei, Taiwan, were conducted. The results reveal that although passengers under less time stress are more likely to perform discretionary activities, the dynamics of store-visiting choices suggest that airport shoppers can be distinguished into two types: shoppers whose store-visiting probability is negatively associated with time stress, and shoppers whose store-visiting probability has a concave relationship with time stress. The effect of visual attractiveness is especially strong for process activities (e.g., passing through security screening and passport control), and the variance in the visual-attractiveness effect for discretionary activities (e.g., shopping) is strongly influenced by the airport environment. The results also indicate novelty-seeking behavior: passengers are less likely to do something that they have already done. Our findings suggest that passengers behave heterogeneously in response to various levels of time stress but homogeneously in response to visual cues. Despite the variation in passenger characteristics, this study demonstrates that trajectory data alone are sufficient for the construction of passenger behavior models with satisfactory temporal transferability.

Concentration and Innovation in the Defence Industry: A Stochastic Game

ABSTRACT The relationship between industry structure, aggregate R&D activity and the quality level of the resulting innovation is investigated in a simple stochastic one-shot game in which all firms share the same probability of attaining the innovation concerning a new weapon system and therefore obtaining the contract from the government. The main findings of the game can be summarised as follows. Although only performing numerical calculations, the model predicts the existence of a concave and single-peaked relationship between aggregate R&D and industry structure, making it desirable to adjust concentration in order to reach that peak. However, the degree of concentration that maximises the final quality level of the innovation is higher than that maximises industry-wide R&D efforts, except in the special case in which technical knowledge freely spills over across firms, thanks to the creation of a research joint venture involving all firms.

Revisiting the Drivers of Firm Value; An Empirical Investigation on Manufacturing Firms

The study aims to ascertain the key determinants of firm value and to analyze the contribution of each determinant at different percentiles of the probability distribution of firm value for 1,592 firms across eight major Indian manufacturing firms. The sample consists of data from 2009 to 2020 and studies the variables such as enterprise value, effective tax rate, firm size, profitability, firms’ growth rate, financial leverage, asset tangibility, and non-debt tax shield. The study employed, linear, non-linear, and non-parametric panel regression models. Quantile regression models are further used to decompose the determinants at various quantiles of firm value. Several diagnostic tests such as Breusch–Pagan, White’s Test, and Sargan Test are used to ensure robust estimates. The results obtained from this study show the presence of a concave relationship between firm value with firm size, financial leverage, and non-debt tax shield. Effective tax rates and inflation rates substantially and positively affect the value of firms in higher percentiles. The capital structure is found to significantly and positively affect the value of firms in the lower percentile. The profitability is also found to contribute to the value of firms across all the quantiles, whereas sales growth fails to strongly drive the value.