A causal analysis of the impact of information systems and supply chain management practices on operational performance: Evidence from manufacturing SMEs in Turkey

This study has empirically tested a framework identifying the causal links among supply chain management (SCM) and information systems (IS) practices, SCM–IS related inhibiting factors and operational performance based on a sample of 203 manufacturing SMEs operating in the manufacture of fabricated metal products and general purpose machinery within the greater metropolitan area of Istanbul in Turkey. Moderating effect of SCM and IS related enabling factors on the above mentioned relationships is also investigated in this study. Tests of hypotheses indicate that both SCM and IS practices positively and significantly influence the operational performance of sample firms. The results of the structural model also indicate a strong support for negative relationships between SCM–IS related inhibitors and the implementation levels of both SCM and IS practices. Similarly, a strong support was found for the hypothesized negative relationship between SCM–IS inhibitors and operational performance of SMEs. Finally, we verified the moderating impact of SCM–IS enablers on the link between SCM practices and operational performance. A similar moderating impact was also found with regard to the relationship between IS practices and operational performance.     

Asymptotics for small nonlinear price impact: A PDE approach to the multidimensional case

We provide an asymptotic expansion of the value function of a multidimensional utility maximization problem from consumption with small nonlinear price impact. In our model, cross‐impacts between assets are allowed. In the limit for small price impact, we determine the asymptotic expansion of the value function around its frictionless version. The leading order correction is characterized by a nonlinear second‐order PDE related to an ergodic control problem and a linear parabolic PDE. We illustrate our result on a multivariate geometric Brownian motion price model.     

ON ARBITRAGE AND DUALITY UNDER MODEL UNCERTAINTY AND PORTFOLIO CONSTRAINTS

We consider the fundamental theorem of asset pricing (FTAP) and the hedging prices of options under nondominated model uncertainty and portfolio constraints in discrete time. We first show that no arbitrage holds if and only if there exists some family of probability measures such that any admissible portfolio value process is a local super‐martingale under these measures. We also get the nondominated optional decomposition with constraints. From this decomposition, we obtain the duality of the super‐hedging prices of European options, as well as the sub‐ and super‐hedging prices of American options. Finally, we get the FTAP and the duality of super‐hedging prices in a market where stocks are traded dynamically and options are traded statically.     

Strict local martingale deflators and valuing American call-type options

We solve the problem of valuing and optimal exercise of American call-type options in markets which do not necessarily admit an equivalent local martingale measure. This resolves an open question proposed by Karatzas and Fernholz (Handbook of Numerical Analysis, vol. 15, pp. 89–167, Elsevier, Amsterdam, 2009).     

The Impact of Intrinsic Religiosity on Consumers’ Ethical Beliefs: Does It Depend on the Type of Religion? A Comparison of Christian and Moslem Consumers in Germany and Turkey

Intrinsic religiosity drives ethical consumer behavior; however, previous studies regarding this connection are limited solely to a Christian cultural context. This comparative study instead includes Christian Consumers from Germany and Moslem Consumers from Turkey to determine if a specific religious community moderates the connection between intrinsic religiosity and consumer ethics. The results show that Consumers in the Turkish, Moslem subsample, exhibit an even stronger connection between religiosity and ethical consumer behavior than Consumers from the German, Christian subsample.     

Pricing options in incomplete equity markets via the instantaneous Sharpe ratio

We use a continuous version of the standard deviation premium principle for pricing in incomplete equity markets by assuming that the investor issuing an unhedgeable derivative security requires compensation for this risk in the form of a pre-specified instantaneous Sharpe ratio. First, we apply our method to price options on non-traded assets for which there is a traded asset that is correlated to the non-traded asset. Our main contribution to this particular problem is to show that our seller/buyer prices are the upper/lower good deal bounds of Cochrane and Saá-Requejo (J Polit Econ 108:79–119, 2000) and of Björk and Slinko (Rev Finance 10:221–260, 2006) and to determine the analytical properties of these prices. Second, we apply our method to price options in the presence of stochastic volatility. Our main contribution to this problem is to show that the instantaneous Sharpe ratio, an integral ingredient in our methodology, is the negative of the market price of volatility risk, as defined in Fouque et al. (Derivatives in financial markets with stochastic volatility. Cambridge University Press, 2000).     

Investigating the need for consumer education among Turkish secondary school students

This study has been planned to determine the need for consumer education by secondary school students. A total of 300 secondary school students (150 female, 150 male) living in central Ankara in different regions with respect to socio‐economic status participated in the study. Consumer education is defined as the management of economic resources, consumer behaviour concepts, relating to consumption, level of knowledge about consumer rights and responsibilities and environmental sensitivity. On the basis of this study, almost half the adolescents draw up a budget plan and carry out market research before shopping. Also, almost half of them put quality first when choosing goods and cost is of secondary importance. More than half of the students save money for unexpected outlay. Nonetheless, adolescents do not know about consumer rights and responsibilities, nor do they have sufficient information about consumer law and the concept of protecting the environment. More than half of the students stated that they need consumer education courses as part of their curriculum.     

Equilibria of time-inconsistent stopping for one-dimensional diffusion processes

We consider three equilibrium concepts proposed in the literature for time-inconsistent stopping problems, including mild equilibria (introduced in Huang and Nguyen-Huu (2018)), weak equilibria (introduced in Christensen and Lindensjö (2018)), and strong equilibria (introduced in Bayraktar et al. (2021)). The discount function is assumed to be log subadditive and the underlying process is one-dimensional diffusion. We first provide necessary and sufficient conditions for the characterization of weak equilibria. The smooth-fit condition is obtained as a by-product. Next, based on the characterization of weak equilibria, we show that an optimal mild equilibrium is also weak. Then we provide conditions under which a weak equilibrium is strong. We further show that an optimal mild equilibrium is also strong under a certain condition. Finally, we provide several examples including one showing a weak equilibrium may not be strong, and another one showing a strong equilibrium may not be optimal mild.