This paper investigates a multi-period stochastic cash flow inventory problem with the aim of maximizing the long-term survival probability, which may be the objective of some retailers especially in ...periods of economic distress. Demand in each period is stochastic and can be non-stationary. In order to avoid too many lost sales under this objective, we introduce a joint chance constraint requiring the probability of no stockouts during the planning horizon to be higher than a specified service level. We develop a scenario-based model and a sample average approximation (SAA) model to solve the problem. A statistical upper bound on the survival probability based on SAA is provided and we discuss upper and lower bounds for the problem based on stochastic dynamic programming. We also propose a rolling horizon approach with service rate updating to test the out-of-sample performance of the two stochastic models and solve problems with long planning horizons. We test the two methods in large numerical tests and find that the rolling horizon approach together with the stochastic models can solve realistically sized problems in reasonable time.
•An extended warranty with trade-ins for the same or upgraded product is emerging.•Whether to sell the traditional extended warranty or the one with trade-in service?•The optimal warranty strategy ...and associated pricing strategies are examined.•Some important findings and insights regarding extended warranties are obtained.
Retailers and manufacturers are increasingly selling extended warranties to obtain high profitability. In addition to the traditional extended warranty (EWR), that offers a free repair and replacement service, a new extended warranty (EWT) comes to the market, under which an additional trade-in service is provided during the warranty coverage. The service provider faces three important decisions: (1) Whether to offer EWR or EWT? (2) How to set the optimal selling prices of EWR and EWT? (3) When choosing to sell EWT, how to determine the optimal trade-in price? To address such challenging issues, we first develop two theoretical models regarding EWR and EWT for a retailer, and further consider the cases where a manufacturer sells the extended warranties and the upgraded product has different failure probabilities. The results show that EWT should never be offered at a higher price than EWR, and when the handling cost for used products is relatively low, EWT will outperform EWR. While the optimal EWR and EWT selling prices increase with the product failure probability, the optimal trade-in price decreases with it. Interestingly, the optimal trade-in discount is not always increasing or decreasing with the failure probability. Moreover, an earlier trade-in time is usually better for the service provider. Compared with the retailer, the manufacturer will always set a lower warranty selling price, but neither of them will always offer a lower trade-in price or discount. We also find that the upgraded product's failure probability will affect the retailer's optimal warranty strategy and profit.
This paper analyses the contract between an entrepreneur and an investor, using a non-zero sum game in which the entrepreneur is interested in company survival and the investor in maximizing expected ...net present value. Theoretical results are given and the model’s usefulness is exemplified using simulations. We have observed that both the entrepreneur and the investor are better off under a contract which involves repayments and a share of the start-up company. We also have observed that the entrepreneur will choose riskier actions as the repayments become harder to meet up to a level where the company is no longer able to survive.
The debate over what counts as credible evidence often occurs on a methodological level (i.e., about what technical applications of systematic inquiry provide believable, justifiable claims about a ...program). Less often, it occurs on an epistemological level (i.e., about what ways of knowing are appropriate for making claims about a program). Even less often, the debate touches on ontological concerns (i.e., about what conceptualizations of reality, in general or in relation to a specific program, are in play when we wish to make claims about that program). For example, whether we understand Extension to be a vehicle for the dissemination of scientific knowledge or a site of grassroots democracy matters when we seek to evaluate Extension with credibility. The purpose of this paper is to examine the credible evidence debates through an ontological lens, showing why and how different narratives (or different realities) of Extension must be considered when we seek credible evidence about Extension.
Bank capital requirements aim at reducing the likelihood of banks' failure. However, these policies may generate externalities on the overall economy. By investigating the pathways from capital ...requirements to housing tenure using structural equation modelling, we show that community banks' capital requirements increase the gap between the regional real estate loans‐based and non‐real estate loans‐based housing purchase rate and act as driving factors of housing market imbalance. The drop in residential real estate loans caused by the increase in capital requirements has two opposite effects: the direct effect motivates residents to rent properties, while the indirect effect motivates residents to purchase them due to the fall in housing prices. When both effects exist in housing purchases with real estate loans, the former effect is more influential than the latter one. Our findings suggest that the impact of capital requirements on housing tenure will depend on residents' reliance on real estate loans. If a housing purchase requires real estate loans, capital requirements will have a negative impact on the housing purchase, and vice versa.
Economic development, variation in weather patterns and natural disasters focus attention on the management of water resources. This paper reviews the literature on the development of mathematical ...programming models for water resource management under uncertainty between 2010 and 2017. A systematic search of the academic literature identified 448 journal articles on water resource management for examination. Bibliometric analysis is employed to investigate the methods that researchers are currently using to address this problem and to identify recent trends in research in the area. The research reveals that stochastic dynamic programming and multistage stochastic programming are the methods most commonly applied. Water resource allocation, climate change, water quality and agricultural irrigation are amongst the most frequently discussed topics in the literature. A more detailed examination of the literature on each of these topics is included. The findings suggest that there is a need for mathematical programming models of large-scale water systems that deal with uncertainty and multiobjectives in an effective and computationally efficient way.
Abstract
Background
There is a need to unpack the empirical, practical, and personal challenges within participatory approaches advocated to optimize implementation. The unpredictable, chaotic nature ...of participatory approaches complicates application of implementation theories, methods, and strategies which do not address researchers’ situatedness within participatory processes. As an implementation scientist, addressing one’s own situatedness through critical reflection is important to unearth how conscious and unconscious approaches, including ontological and epistemological underpinnings, influence the participatory context, process, and outcomes. Therefore, the aim of this exploratory work is to investigate the heretofore blind spot toward the lived experience of implementation researchers within the participatory process.
Methods
We developed an integrated research-practice partnership (IRPP) to inform the implementation of a gestational weight gain (GWG) control program. Within this IRPP, one investigator conducted a 12-month autoethnography. Data collection and triangulation included field notes, cultural artifacts, and systematic timeline tracking. Data analysis included ethnographic-theoretical dialogue and restorying to synthesize key events and epiphanies into a narrative.
Results
Analysis revealed the unpredicted evolution of the GWG program into a maternal health fair and three themes within the researchers’ lived experience: (1) permeable work boundaries, (2) individual and collective blind spots toward the ontological and epistemological underpinnings of implementation paradigms, and (3) maladaptive behaviors seemingly reinforced by the research culture. These themes contributed to the chaos of implementation and to researchers’ experience of inadequate recovery from cognitive, emotional, and practical demands. These themes also demonstrated the importance of contextual factors, subjectivity, and value-based judgments within implementation research.
Conclusion
Building on extant qualitative research guidelines, we suggest that researchers anchor their approach to implementation in reflexivity, intentionally and iteratively reflecting on their own situatedness. Through this autoethnography, we have elucidated several strategies based on critical reflection including examining philosophical underpinnings of research, adopting restorative practices that align with one’s values, and embracing personal presence as a foundation of scientific productivity. Within the predominant (post-) positivism paradigms, autoethnography may be criticized as unscientifically subjective or self-indulgent. However, this work demonstrates that autoethnography is a vehicle for third-person observation and first-person critical reflection that is transformative in understanding and optimizing implementation contexts, processes, and outcomes.
Background: Evaluation is an increasingly vital component of community and economic development projects in Africa. Yet questions remain about how relevant most evaluation approaches for the African ...evaluation context. Within the ‘Made in Africa’ (MAE) approach, ubuntu is frequently cited as an African philosophical concept with salience to MAE. There is a need to further expand and explicate other African philosophies that can serve as epistemological guideposts for African evaluation—and other decolonizing, indigenous evaluation approaches more broadly.
Purpose: Drawing on Ghanaian epistemologies and frameworks, the purpose of this paper is to propose the Nnoboa system of communal collaboration in farming and industry, as well as the notion of Sankofa as a traditional philosophical concept that irrupts and challenges hegemonic Eurocentric notions of the linearity of time, to yield a Ghanaian indigenous knowledge of evaluation.
Setting: Not applicable.
Intervention: Not applicable.
Research Design: This conceptual study draws on literature on culturally responsive evaluation (CRE), MAE, and (from beyond the field of evaluation), descriptions of Nnoboa and Sankofa to propose a conceptual synthesis applicable to decolonizing, indigenous evaluation.
Data Collection and Analysis: Not applicable.
Findings: We propose that Nnoboa and Sankofa represent an addition to the decolonizing and indigenous evaluation knowledge base, building on and going beyond the reliance of CRE and MAE in ubuntu. We propose this Ghanaian approach has potential applications across MAE and CRE more broadly.
Background: African evaluation has been at the forefront of innovating the praxis of decolonizing evaluation, especially through ‘Made in Africa Evaluation’ (MAE) and related efforts. Still, there is ...a wealth of additional African epistemologies and philosophical paradigms which either have not been adequately discussed in the literature, or have not yet made their way into the discourse and practice of MAE.
Purpose: The purpose of this conceptual paper is to propose a theoretical framework that can be used to further inform indigenous and decolonizing evaluation approaches in African contexts and beyond. Specifically, we address the often-cited notion of ubuntu, informed by African philosophical literature beyond the field of evaluation, and we propose Sylvia Tamale’s decolonizing and Afro-feminist lens as a complementary philosophical framing with great potential applications in indigenous and decolonizing evaluation in African contexts and beyond.
Setting: Not applicable.
Intervention: Not applicable.
Research Design: This conceptual study draws on philosophical literature from African philosophy and political science to weave together notions of ubuntu with decolonizing Afro-Feminism.
Data Collection and Analysis: Not applicable.
Findings: We propose that a decolonizing, indigenous evaluation approach rooted in Ubuntu and Afro-Feminism would: question categorial, dichotomous, hierarchical logics (e.g., methodological hierarchical hegemonies); recognize masculinist, imperialist, modernist ideals inscribed in institutions (e.g., via government rationality, therefore also via evaluation); foreground intersectionality; and make room for “the moral economy” and other deeply communitarian framings.
Existing studies suggest levying a systemic risk tax on systemically important banks to cover the costs of governmental interventions in (bailing out) these banks in the case of their bankruptcies. ...We develop a static model to investigate how this tax would affect the banks' equilibrium capital holdings and its impacts on banks’ optimal capital regulations in terms of social welfare. We find that this tax would not only result in a safer banking system but would also help to mitigate the pro-cyclical effects of banking capital requirements. However, these merits would come at the cost of an increase in loan rate. Moreover, the improvements of the tax are less pronounced when the capital requirements are relatively strict as, for example, in Basel III. Regarding welfare, Basel II is closer to the optimal level. Although Basel III results in a safer banking system, this improvement compromises social welfare. Our findings also suggest that regulators should set higher capital requirements for systemically important banks, which is similar to the rules in Basel III.
•We estimate the optimal capital requirements for systematically important banks and non-systematically important banks.•We investigate the impacts of levying a systematic tax on banks and the real economy.•We provide numerical evidence to support the validity of Basel III in maintaining financial stability.•We suggest that the government could also regulate (systematically important) banks through appropriate taxation.