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We develop a novel control function approach in models where the treatment variable has bunching at one corner of its support. This situation typically arises when the treatment variable is a constrained choice and some observations choose the corner solution. The method exploits distributional shape restrictions but makes no exclusion restrictions. We provide estimators and establish their asymptotic behavior, prove the convergence of the bootstrap, and develop tests of the identification assumptions. An application reveals that watching television has no effect on cognitive skills and a negative effect on noncognitive skills in children. [ABSTRACT FROM AUTHOR]

We present simple procedures for estimating non linear panel data models in the presence of unobserved heterogeneity and possible endogeneity with respect to time-varying unobservables. We combine a correlated random effects approach with a control function approach while accounting for missing time periods for some units. We examine the performance of the approach in comparisons with standard estimators using Monte Carlo simulation. We apply the methods to estimate the effects of school spending on student pass rates on a standardized math exam. We find that a 10% increase in spending leads to an approximately 2 percentage point increase in math pass rates. [ABSTRACT FROM AUTHOR]

We examine the impact of firm social media engagement on sales performance, answering “whether,” “what,” and “how” questions. The study uses a quasi-experimental design in a social e-commerce setting, for which propensity score matching and difference-in-differences methods quantify a mean 20.67% sales increase after firm social media adoption. We also find that firms that sell low-involvement products benefit more from social media adoption, compared to those that sell high-involvement products. Further, in terms of how to manage social media engagement, we find that informative content, in general, is effective for sales of high-involvement products, whereas promotional content, a new type of content discovered in this study, is more beneficial for sales of low-involvement products. Meanwhile, more social media followers generate better firm sales performance. We used instrumental variables and the control function method to address endogeneity issues and conducted robustness checks to support our conclusions. This study sheds light on the value of firm social media, particularly regarding industry differences and firm know-how. [ABSTRACT FROM AUTHOR]

This paper presents some existence and uniqueness results for a system of mappings on the finite product of metric spaces. Our results extend and generalize the well-known and celebrated results of Boyd and Wong [Proc. Amer. Math. Soc. 20 (1969)], Matkowski [Dissertations Math. (Rozprawy Mat.) 127 (1975)], Proinov [Nonlinear Anal. 64 (2006)], Song-il Ri [Indag. Math. (N. S.) 27 (2016)] and many others. We also present some illustrative examples to validate our results.

This paper considers the problem of inferring the causal effect of a variable Z on a dependently censored survival time T. We allow for unobserved confounding variables, such that the error term of the regression model for T is dependent on the confounded variable Z. Moreover, T is subject to dependent censoring. This means that T is right censored by a censoring time C, which is dependent on T (even after conditioning out the effects of the measured covariates). A control function approach, relying on an instrumental variable, is leveraged to tackle the confounding issue. Further, it is assumed that T and C follow a joint regression model with bivariate Gaussian error terms and an unspecified covariance matrix, such that the dependent censoring can be handled in a flexible manner. Conditions under which the model is identifiable are given, a two-step estimation procedure is proposed, and it is shown that the resulting estimator is consistent and asymptotically normal. Simulations are used to confirm the validity and finite-sample performance of the estimation procedure. Finally, the proposed method is used to estimate the causal effect of job training programs on unemployment duration. [ABSTRACT FROM AUTHOR]

In this study, we investigate a penalty-based two-stage least square estimator in regression models when the exploratory variables are correlated with the error term. We propose a two-stage Bridge estimator to overcome this endogeneity problem in high-dimensional data. Our proposed estimator enjoys remarkable statistical properties such as consistency and asymptotic normality. As special cases, this method deals some ill-condition situations such as the multicollinearity as well as the sparsity. Performance of the proposed estimators is demonstrated by simulation studies and it is compared to the existing estimators. An application in real data set is presented for illustration. [ABSTRACT FROM AUTHOR]

Summary: We study approaches for adjusting machine learning methods when the training sample differs from the prediction sample on unobserved dimensions. The machine learning literature predominately assumes selection only on observed dimensions. Common approaches are to weight or include variables that influence selection as solutions to selection on observables. Simulation results show that selection on unobservables increases mean squared prediction error using popular machine‐learning algorithms. Common machine learning practices such as weighting or including variables that influence selection into the training or prediction sample often worsen sample selection bias. We propose two control function approaches that remove the effects of selection bias before training and find that they reduce mean‐squared prediction error in simulations. We apply these approaches to predicting the vote share of the incumbent in gubernatorial elections using previously observed re‐election bids. We find that ignoring selection on unobservables leads to substantially higher predicted vote shares for the incumbent than when the control function approach is used. [ABSTRACT FROM AUTHOR]

In this paper, in the view of control functions, the existence of periodic solutions of the following second-order discrete Hamiltonian system $ \bigtriangleup ^{2} u(n-1) = \nabla F(n, u(n)), \ \ n\in \mathbb{Z} $ with a generalized sublinear condition is further explored.

We propose a parametric estimation procedure for linear panel data models with sample selection and heterogeneous coefficients that are present in both outcome model and selection model. Our two‐step estimation procedure accounts for endogeneity from the selection process and endogeneity from correlation between the individual unobserved heterogeneity and the observed covariates using control function like methods. Conditional linear projections are used to establish a tractable approach that builds upon the original Heckman correction to sample selection. Monte Carlo simulations illustrate the finite sample properties of our estimator and demonstrate that our proposed estimator outperforms standard estimators. We apply the proposed approach to estimate gender differences in high‐stakes time‐constrained decisions using Elo ratings data from the World Chess Federation. When addressing both sources of endogeneity, we find a much larger gender skill gap and substantial differences across the genders in strategically selecting into time‐constrained matches. [ABSTRACT FROM AUTHOR]

This paper presents some existence and uniqueness results for a solution of a system of equations. Our results extend and generalize the well-known and celebrated results of Boyd and Wong [Proc. Amer. Math. Soc. 20 (1969)], Matkowski [Dissertations Math. (Rozprawy Mat.) 127 (1975)], Proinov [Nonlinear Anal. 64 (2006)], Ri [Indag. Math. (N. S.) 27 (2016)] and many others. We also present some illustrative examples to validate our results. [ABSTRACT FROM AUTHOR]

Copyright of Revista Internacional CONSINTER de Direito is the property of JURUA EDITORIAL and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Dokuz Eylül University Law Review is the property of Dokuz Eyluel University, Faculty of Law Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We examine the relationship between investments in animal breeding and productivity growth on Wisconsin dairy farms using a control function approach. We incorporate farm‐level annual investment in breeding and genetics into the law of motion of productivity as in De Loecker (2013) to test the relationship between these investments and realized productivity. Our unique dataset also allows us to look at the effect of choosing bulls with high milk yield potential on productivity. Our results indicate that breeding investments made 3 years prior are associated with higher productivity of the current cohort. However, the farms with the highest level of productivity reap the lowest benefits from breeding investments, suggesting that there are diminishing returns to investing in genetics. When milk output is not quality adjusted, the contribution of breeding to productivity is undetectable, suggesting that breeding and investments in milk quality are related. We conclude that investments in breeding and genetics significantly contribute to dairy farm productivity, especially in terms of milk quality. [ABSTRACT FROM AUTHOR]

In this paper, we propose a method to determine the state function and control function of the dynamical system represented by a system of equations with first-order partial derivatives under boundary and the first-order partial derivatives conditions of state function where are real matrices with corresponding sizes. The basis of the theory is a method to prove the orderable cascade decomposition to transform the original system into the equivalent system in the type . In the final step, we obtain the state function satisfying the conditions and substituting this in the previous step. Continuing this process, we can find out the state function and controllable function of the original dynamical system.

Two player pursuit evasion differential game and time optimal zero control problem in ℓ2 are considered. Optimal control for the corresponding zero control problem is found. A strategy for the pursuer that guarantees the solution for the pursuit problem is constructed. [ABSTRACT FROM AUTHOR]

In this paper, the work is concerned with the study of moving boundary based on non-classical heat equation that includes a time dependent heat flux and convection. The latent heat is represented as a function of the moving interface. Mathematical model accounts for a control function varying with heat flux. We have obtained the explicit solution of the given mathematical model in the presence of convection and a control function. The Legendre wavelet Galerkin approach (LWGA) is used to solve the mathematical problem. In a particular case, our numerical results were compared with previous results and found to be in excellent agreement. Moreover, the current numerical technique is more efficient and accurate in comparison to the previous available method. An extensive analysis of the problem parameters is presented. It is found that the control function offers a significant contribution during the melting or freezing of a PCM. A greater value of the heat flux accelerates the rate of propagation of interface. Convection heat transfer increases the speed of the interface. Results obtained from the current study are expected to improve the fundamental understanding of heat transfer and aid in sublimation and desorption like physical phenomena. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Sports Creativity is the property of Journal of Sports Creativity and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of China University of Petroleum is the property of China University of Petroleum and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper investigates relative controllability of impulsive linear discrete delay systems with constant coefficients and a pure delay. Grammian and rank criteria for relative controllability are respectively established by introducing an impulsive discrete delay Grammian matrix. Thereafter, the restricted relative controllability of impulsive linear discrete delay systems is studied. More precisely, when the terminal state locates in a special invariant linear subspace, Grammian and rank criteria for relative controllability are demonstrated and an expression of corresponding control function is constructed. Finally, an example is provided to illustrate theoretical results. [ABSTRACT FROM AUTHOR]

This article considers a semiparametric threshold regression model with two threshold variables. The proposed model allows endogenous threshold variables and endogenous slope regressors. Under the diminishing threshold effects framework, we derive consistency and asymptotic results of our proposed estimator for weakly dependent data. We study the finite sample performance of our proposed estimator via small Monte Carlo simulations and apply our model to classify economic growth regimes based on both national public debt and national external debt. [ABSTRACT FROM AUTHOR]

The dynamic problem of the optimal rotation of a rigid body (for example, a spacecraft) from an arbitrary initial to a designated final angular position in the presence of restrictions on the control variables is studied. Rotation time is not fixed. To optimize the rotation control program, a combined quality criterion is used, the minimized functional combines the energy costs and the duration of the maneuver in a given proportion. Based on the L. S. Pontryagin maximum principle and quaternion models of controlled motion of a solid, a solution to the problem was obtained. The reorientation optimality conditions are written in analytical form, and the properties of optimal rotation are shown. To construct an optimal rotation program, formalized equations and calculation formulas are written. Optimal control is presented in the form of a synthesis. The control law is formulated as an explicit dependence of the control variables on the phase coordinates. Analytical equations and relations for finding the optimal motion are given. Key relationships are given that determine the optimal values of the parameters of the rotation control algorithm. A constructive scheme for solving the boundary value problem of the maximum principle for arbitrary rotation conditions (initial and final positions and moments of inertia of a rigid body) is also described. For a dynamically symmetric rigid body, a closed-form solution of the reorientation problem is obtained. A numerical example and the results of mathematical modeling are presented, demonstrating the practical feasibility of the developed method for controlling the attitude of a spacecraft. [ABSTRACT FROM AUTHOR]

In this paper, we study the pursuit-evasion problem for inertial motions of players. Here, the players' controls are selected from the class of functions that satisfy of the Langenhope type integral inequalities. The physical interpretation of such constraints on controls is close to energy constraints, similar to integral constraints. To solve the pursuit problem, a parallel approach strategy (briefly, a -strategy) is defined for the pursuer. To solve the evasion problem, the evader's control with delayed information about the pursuer's control is determined. New sufficient conditions for the finding solutions of the pursuit-evasion problem are obtained. This work is a development of the works of R. Isaacs, L.A. Petrosyan, B.N. Pshenichny, A.A. Azamov, N.N. Petrov and others, including the authors of this article. [ABSTRACT FROM AUTHOR]

This paper presents the dynamical aspects of a nonlinear multi-term pantograph-type system of fractional order. Pantograph equations are special differential equations with proportional delays that are employed in many scientific disciplines. The pantograph mechanism, for instance, has been applied in numerous scientific disciplines like electrodynamics, engineering, and control theory. Because of its key rule in diverse fields, the current study establishes some necessary criteria for its controllability. The main idea of the proof is based on converting the system into a fixed point problem and introducing a suitable controllability Gramian matrix $ \mathcal{G}_{c} $. The Gramian matrix $ \mathcal{G}_{c} $ is used to demonstrate the linear system's controllability. Controllability criteria for the associated nonlinear system have been established in the sections that follow using the Schaefer fixed-point theorem and the Arzela-Ascoli theorem, as well as the controllability of the linear system and a few key assumptions. Finally, a computational example is listed.

In this paper, we prove some common fixed point theorems in S-metric spaces for a pair of weakly compatible self-mappings using control function and give some consequences of the established result. We also furnish some examples to demonstrate the validity of the results. The results presented in this paper generalize, extend and enrich several results in the existing literature. [ABSTRACT FROM AUTHOR]

Poverty remains a substantial threat in rural areas of many developing countries, and solving this problem requires an in‐depth understanding of the income generating capacity that determines poverty. This paper examines the impact of agricultural commercialisation on the capability of rural households to accumulate and productively use assets and reduce structural and multidimensional poverty. A longitudinal dataset of around 2000 households with a total of 9781 observations from five rural surveys undertaken in the period 2008–2017 in Vietnam is used. Results from a fixed effects regression with an instrumental variable and a control function approach show that agricultural commercialisation has a positive effect on the accumulation of assets and reduces multidimensional and structural poverty over time. However, the effect is not homogeneous and is larger for households that are not mainly engaged in rice commercialisation. This suggests that commercialisation can be a path out of poverty, especially if policy makers move towards utilising other crops instead of rice. [ABSTRACT FROM AUTHOR]

The effects of reading habits on academic performances have been carefully investigated, but little is known about the effects of academic achievements on students' leisure reading. This paper investigates this issue by estimating the effects of academic achievements, proxied by the number of exams passed, on leisure reading, measured by the number of leisure books read in a year. Using an online survey submitted to the students at the University of Bologna, Italy, we adopt a two‐step control‐function technique to control for endogeneity. The empirical evidence suggests the existence of a negative relationship between students' academic achievements and the time devoted to leisure reading. This result holds for students of different fields of study and is stronger for male students. The Blinder–Oaxaca decomposition supports the existence of a gender‐specific idiosyncratic effect. [ABSTRACT FROM AUTHOR]

The purpose of this article is to establish some common fixed point results for generalized contractions including some precise control functions of two variables in the setting of controlled metric spaces. As consequences of our leading results, we derive common fixed point and fixed point results for contractions with control functions of one variable and constants. We also discuss controlled metric spaces endowed with a graph and obtain some common fixed point results in this newly introduced space. As an application of our leading result, we examine the solution of a Fredholm type integral equation.

This paper presents the dynamical aspects of a nonlinear multi-term pantograph-type system of fractional order. Pantograph equations are special differential equations with proportional delays that are employed in many scientific disciplines. The pantograph mechanism, for instance, has been applied in numerous scientific disciplines like electrodynamics, engineering, and control theory. Because of its key rule in diverse fields, the current study establishes some necessary criteria for its controllability. The main idea of the proof is based on converting the system into a fixed point problem and introducing a suitable controllability Gramian matrix . The Gramian matrix is used to demonstrate the linear system's controllability. Controllability criteria for the associated nonlinear system have been established in the sections that follow using the Schaefer fixed-point theorem and the Arzela-Ascoli theorem, as well as the controllability of the linear system and a few key assumptions. Finally, a computational example is listed. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Derecho Politico is the property of Editorial UNED and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Regression discontinuity is popular in finding treatment/policy effects when the treatment is determined by a continuous variable crossing a cutoff. Typically, a local linear regression (LLR) estimator is used to find the effects. For binary response, however, LLR is not suitable in extrapolating the treatment, as in doubling/tripling the treatment dose/intensity. The reason is that doubling/tripling the LLR estimate can give a number out of the bound [ − 1 , 1 ] , despite that the effect should be a change in probability. We propose local maximum likelihood estimators which overcome these shortcomings, while giving almost the same estimates as the LLR estimator does for the original treatment. A simulation study and an empirical analysis for effects of an income subsidy program on religion demonstrate these points. [ABSTRACT FROM AUTHOR]

Smart transformation and green development are the core research directions of electric vehicles. An electric tractor is powered by the vehicle battery. The motor converts electric energy into mechanical energy and drives the wheels through the drive train. Therefore, the electric tractor model is a modular mathematical model for the battery, motor, drive train, and drive wheel. A class of high-order terminal sliding mode control strategies is adopted to establish the relative rotational angles of drive wheels, driving angular speeds, and motor angular speeds as input, and driving angular speeds and motor angular speeds as output. This process ensures stable operating speed and good working quality under the operating conditions and achieves small-scale unattended driving. The output is a nonlinear system state equation. An n-order derivative continuous function is introduced to design the terminal sliding surface of the sliding mode. A control function to reduce chattering is also designed to ensure that the output function converges at the finite time and the existing sliding stage achieves zero steady-state error. Simulation results of the whole electric tractor model show that the speed remains stable under the condition of outside interference, and experiments verify the feasibility of the control strategy. [ABSTRACT FROM AUTHOR]

Copyright of Human Review is the property of Eagora Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A quaternion solution of the dynamic problem on the optimal turn of a solid (for example, a spacecraft) from a known initial to a given final angular position is presented. Optimization of the control program is carried out by using a combined indicator that combines a quadratic performance criterion and turn time; the minimized functional combines energy costs and maneuver duration in a given proportion. Based on the maximum principle, quaternion models, and methods for studying the controlled motion of a solid (spacecraft), a solution of the problem has been obtained. The construction of the optimal rotation is based on a differential equation relating the angular momentum and the orientation quaternion of a solid. The conditions of optimality are written in analytical form and the properties of the optimal motion are studied. Analytical equations and calculation formulas for finding the optimal control are presented. The control law is formulated as an explicit dependence of the control variables on the phase coordinates. Key relations that determine the optimal values of the parameters of the angular momentum control algorithm are given. In the case of a dynamically symmetric body, a complete solution of the turn problem in a closed form is obtained: analytical dependences as explicit functions of time for control variables and relations for calculating the parameters of the control law are given. A numerical example and the results of numeric simulation of the rotation of a spacecraft as a solid under optimal control that demonstrate the practical feasibility of the proposed control method are given. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to prove coupled fixed point theorems for contractive type conditions involving control function in the setting of partial metric spaces. Also, we give an example to support the result. We demonstrate that the coupled fixed point problem is well-posed. Furthermore, we provide some consequences of the established result. The results of findings in this paper extend and generalize several previously published findings from the existing literature. [ABSTRACT FROM AUTHOR]

Two player pursuit evasion differential game and time optimal zero control problem in ℓ2 are considered. Optimal control for the corresponding zero control problem is found. A strategy for the pursuer that guarantees the solution for the pursuit problem is constructed.

By using a class of aggregation control functions, we introduce the concept of multiple-HU- O S 1 -stability and get an optimum approximation for a nonlinear single fractional differential equation (NS-ABC-FDE) with a Mittag–Leffler kernel. We apply an alternative fixed-point theorem to prove the existence of a unique solution and the multiple-HU- O S 1 -stability for the NS-ABC-FDE in the symmetric matrix-valued FBS. Finally, with an example, we show the application of the obtained results. [ABSTRACT FROM AUTHOR]

This paper investigates the role of land rental markets in livelihood choices using data from 792 farming households in rural Vietnam. First, we cluster households according to livelihood strategies and estimate the determinants of the respective decision. In a second step, we analyze the contribution of rented land in linking smallholders to output markets. Our results suggest that rented land can provide smallholders with an opportunity to increase their agricultural activities and avoid resorting to less remunerative activities such as agricultural wage labor. Moreover, rented crop area increases the probability of market participation as well as the quantity of sales. Our results point to the need for a further liberalization of land rental markets specifically targeted at households that have been excluded from more remunerative livelihood strategies previously. Supporting these households to have access to the assets required to cultivate the additional area is thus recommended. [ABSTRACT FROM AUTHOR]

This paper studies the impact of education on domestic terrorism in Asian countries from 1970 to 2018. A control function approach is utilized to address the endogeneity of education on terrorism. Generally speaking, results show that education promotes domestic terrorism in Asia. Negative binomial regressions with and without control function are run for other parts of world to examine whether the patterns in Asia hold worldwide. Other important determinants of domestic terrorism in Asia include regime type, ethnic fractionalization, linguistic fractionalization, religious fractionalization, GDP per capita, and trade openness. This paper contributes to the literature by 1) applying a control function approach to control for possible endogeneity of education on terrorism, 2) analyzing exclusively Asia, a region where terrorism has been increasing rapidly over the last decade, (3) and focusing on domestic terrorism. [ABSTRACT FROM AUTHOR]

Recently, the idea of φ-fixed point and the elementary results on φ-fixed points were first investigated by Jleli et al. [Jleli M, Samet B, Vetro C (2014) Fixed point theory in partial metric spaces via φ-fixed point's con- cept in metric spaces. Journal of Inequalities and Applications, 2014(1):1- 9.]. Based on this work, Karapinar et al. [Karapinar E, O'Regan D, Samet B (2015) On the existence of fixed points that belong to the zero set of a certain function. Fixed Point Theory and Applications, 2015(1):1-14.] established the new φ-fixed point results, which can be reduced to the famous fixed point result of Boyd and Wong in 1969. However, the main result of Karapinar et al. does not cover the φ-fixed point results of Jleli et al. This paper aims to fulfill this gap by proving φ-fixed point results covering several φ-fixed point results and fixed point results [ABSTRACT FROM AUTHOR]

There is an extensive literature that links firms’ access to formal financial services and trade credit. This is more relevant for firms operating in financially less developed countries. These firms could potentially face a binding bank loan constraint due to the distortions related to information asymmetry and moral hazard. Against this backcloth, this paper will explore the relationship between trade credit and financial constraints for Ethiopian firms. The main objective of this study is to explore the relationship between trade credit practice and financial constraints for Ethiopian manufacturing and service firms. We exploit the repeated cross-sectional data of 2011 and 2015 made available by the World Bank’s Ethiopian Enterprise Survey. To address the endogeneity problem between financial constraint and trade credit, the paper employs an instrumental variable (IV) approach. We find a negative relationship between financial constraint and trade credit use. In particular, financially constrained firms have a trade credit use which is about 10 to 18 percentage points lower than unconstrained firms, suggesting that bank credit constrained firms are also trade credit constrained. One policy implication is that addressing constraints in formal financing is more likely to increase the availability of alternative forms of finance such as trade credit.

Multiple previous reports have established that climate change disproportionately impacts smallholder farmers in developing countries. This study investigates the impact of climate change adaptation, defined by farmers’ decisions to adopt the improved practices to mitigate or reduce the effects of climate change, on crop revenue and revenue risk exposure. We employ the control function approach in an endogenous switching regression framework to account for selection bias. Using the household survey data from Nepal, we find that climate change adaptation positively affects crop revenue and revenue risk reduction. Specifically, climate change adaptation leads to a 21.6% increase in farm revenue and a 6.4% reduction in downside risk exposure, which are robust to several specifications. Counterfactual analysis shows the considerable heterogeneities in the outcomes among adapters and non-adapters. In particular, adapting farm households realize substantial and distinguishable gains in revenues and declines in risk levels relative to their non-adapting peer households. Our findings imply that adapting to climate change can be an effective management practice to mitigate the risks associated with climate change and increase resilience.

In this study, we obtain certain coupled fixed-point results for generalized contractions involving two control functions in a controlled metric space. Additionally, we establish some coupled fixed-point results in graph-enabled controlled metric spaces. Many well-known results from the literature will be expanded upon and modified by our results. In order to demonstrate the validity of the stated results, we also offer some examples. Finally, we apply the theoretical results to obtain the solution to a system of integral equations. [ABSTRACT FROM AUTHOR]

In this paper, we adopt a new approach to study the controllability and observability of linear quaternion-valued systems (QVS) from the point of complex-valued systems, which is much different from the method used in the previous paper. We show the equivalence relation of complete controllability for linear QVS and its complex-valued system. Then we establish two effective criteria for controllability and observability of the linear QVS in the sense of complex representation. In addition, we give a direct method to solve the control function. Finally, we use numerical examples to illustrate our theoretical results. [ABSTRACT FROM AUTHOR]

Natural disasters raise challenging trade-offs between public health safety and inalienable rights like the active involvement in political choices through voting. We exploit a quasi-experimental setting provided by multiple ballots across regions and municipalities during the Italian 2020 elections to estimate the effect of voters' turnout on the spread of COVID-19. By employing an event-study design with a two-stage Control Function strategy, we find that post-poll new COVID infections increased by an average of 1.1% for each additional percentage point of turnout. Based on these estimates and real political events, we also show through a simulation that in-person voting during a high-infection regime may have a large impact on public health outcomes, more than doubling new infections, deaths and hospitalizations. These findings suggest that policy-makers' responses to natural disasters should be flexible and contingent to the emergency severity, in order to minimize social costs for citizens. [ABSTRACT FROM AUTHOR]

Smart transformation and green development are the core research directions of electric vehicles. An electric tractor is powered by the vehicle battery. The motor converts electric energy into mechanical energy and drives the wheels through the drive train. Therefore, the electric tractor model is a modular mathematical model for the battery, motor, drive train, and drive wheel. A class of high-order terminal sliding mode control strategies is adopted to establish the relative rotational angles of drive wheels, driving angular speeds, and motor angular speeds as input, and driving angular speeds and motor angular speeds as output. This process ensures stable operating speed and good working quality under the operating conditions and achieves small-scale unattended driving. The output is a nonlinear system state equation. An n-order derivative continuous function is introduced to design the terminal sliding surface of the sliding mode. A control function to reduce chattering is also designed to ensure that the output function converges at the finite time and the existing sliding stage achieves zero steady-state error. Simulation results of the whole electric tractor model show that the speed remains stable under the condition of outside interference, and experiments verify the feasibility of the control strategy.

In this paper, we prove some coupled fixed point theorems for contractive type conditions using control function in the setting of partial b-metric spaces and provide some corollaries of the main results. We also give an example to illustrate the result. The results presented in this paper extend and generalize several results from the existing literature (see, for example, [1, 24] and many others). [ABSTRACT FROM AUTHOR]

Many stated preference studies have shown that individuals' attitudes play an important role in explaining their behaviour and helping to disentangle preference heterogeneity. When responses to attitudinal questions are introduced into discrete choice models, a suitable approach that corrects for potential endogeneity must be adopted. We use a discrete choice experiment to analyse the preferences of residents regarding the use of agri‐environmental practices in the peri‐urban area of Milan (Italy). A detailed analysis of these preferences is relevant for policymakers as farmers on the peri‐urban fringe are often asked to provide environmental services to urban‐dwellers. We apply a latent class model that we extend to include indicators of individuals' attitudes towards the relationship between agriculture and the environment. Besides the application of the control function approach to deal with endogeneity, our main contribution is the use of a refutability test to check the exogeneity of the instruments in the agri‐environmental setting. Our results show that attitudinal indicators help to disentangle the preference heterogeneity and that the respondents' willingness‐to‐pay distribution differs according to the indicators' values. [ABSTRACT FROM AUTHOR]