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The majority of recent empirical papers in operations management (OM) employ observational data to investigate the causal effects of a treatment, such as program or policy adoption. However, as observational data lacks the benefit of random treatment assignment, estimating causal effects poses challenges. In the specific scenario where one can reasonably assume that all confounding factors are observed—referred to as selection on observables—matching methods and synthetic controls can assist researchers to replicate a randomized experiment, the most desirable setting for drawing causal inferences. In this paper, we first present an overview of matching methods and their utilization in the OM literature. Subsequently, we establish the framework and provide pragmatic guidance for propensity score matching and coarsened exact matching, which have garnered considerable attention in recent OM studies. Following this, we conduct a comprehensive simulation study that compares diverse matching algorithms across various scenarios, providing practical insights derived from our findings. Finally, we discuss synthetic controls, a method that offers unique advantages over matching techniques in specific scenarios and is expected to become even more popular in the OM field in the near future. We hope that this paper will serve as a catalyst for promoting a more rigorous application of matching and synthetic control methodologies. [ABSTRACT FROM AUTHOR]

Sexual self-concept (SSC) is a person's perception of themself as a sexual being. SSC is a key construct in understanding people's sexuality. However, the extent to which sexuality researchers consistently define, measure, and evaluate SSC is unknown. In this review, we determine the common elements of researchers' conceptual definitions of SSC (RQ1), describe how researchers measure SSC (RQ2), examine the structural (RQ3) and external (RQ4) validity of these measures, and (highlight who is represented in the creation of SSC measures (RQ5). We conducted a comprehensive review of 67 peer-reviewed SSC studies identified through a systematic search of five databases. We extracted data using Loevinger's (1957) three phases of construct validation: substantive, structural, and external. Our results highlight current limitations in SSC construct validity. Of the 67 studies, 50 provided a conceptual SSC definition, including 14 unique definitions. Additionally, there were 32 unique measures of SSC, providing 34 distinct subscales. White (38.3%), female (47.8%), and North American (47.8%) participants were mostly represented in the research; sexual minoritized people's perceptions were underrepresented. We discuss the importance of having consistent theory-driven definitions of SSC. Moreover, researchers must consider how different groups of people uniquely understand and construct their SSCs to improve knowledge. [ABSTRACT FROM AUTHOR]

Necessary condition analysis (NCA) is an increasingly used or suggested method in many business and management disciplines including, for example, entrepreneurship, human resource management, international business, marketing, operations, public and nonprofit management, strategic management, and tourism. In the light of this development, our work delivers a review of the topics analyzed with NCA or in which NCA is proposed as a method. The review highlights the tremendous possibilities of using NCA, which hopefully encourages other researchers to try the method. To support researchers in future NCA studies, this article also provides detailed guidelines about how to best use NCA. These cover eight topics: theoretical justification, meaningful data, scatter plot, ceiling line, effect size, statistical test, bottleneck analysis, and further descriptions of NCA. [ABSTRACT FROM AUTHOR]

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This study aims to identify whether different research methods linking ISO 9001 and performance have led to different results. To achieve that purpose, this study conducted a method review using scholarly articles selected from seven databases. Sixty-nine percent of previous cross-sectional studies linking ISO 9001 and performance concluded that there is a positive relationship between ISO 9001 and performance, while 77% of previous longitudinal studies did not find a relationship. The way the two methods acknowledged time sequence and certification and the inconsistency in terminologies and indicators might be the reasons behind the strikingly different research results. However, this study neither gauged the impact of each article to the field of the quality system nor the power of statistical tools used to indicate causality. This study also constrained by the limited resource. A method review is rare in the field of ISO 9001 and performance and currently, it is highly needed because after 30 years of research, there is still no sign of research results convergence. [ABSTRACT FROM AUTHOR]

Purpose: The safeguard subject of the Area of Protection "natural Resources," particularly regarding mineral resources, has long been debated. Consequently, a variety of life cycle impact assessment methods based on different concepts are available. The Life Cycle Initiative, hosted by the UN Environment, established an expert task force on "Mineral Resources" to review existing methods (this article) and provide guidance for application-dependent use of the methods and recommendations for further methodological development (Berger et al. in Int J Life Cycle Assess, 2020). Methods: Starting in 2017, the task force developed a white paper, which served as its main input to a SETAC Pellston Workshop® in June 2018, in which a sub-group of the task force members developed recommendations for assessing impacts of mineral resource use in LCA. This article, based mainly on the white paper and pre-workshop discussions, presents a thorough review of 27 different life cycle impact assessment methods for mineral resource use in the "natural resources" area of protection. The methods are categorized according to their basic impact mechanisms, described and compared, and assessed against a comprehensive set of criteria. Results and discussion: Four method categories have been identified and their underlying concepts are described based on existing literature: depletion methods, future efforts methods, thermodynamic accounting methods, and supply risk methods. While we consider depletion and future efforts methods more "traditional" life cycle impact assessment methods, thermodynamic accounting and supply risk methods are rather providing complementary information. Within each method category, differences between methods are discussed in detail, which allows for further sub-categorization and better understanding of what the methods actually assess. Conclusions: We provide a thorough review of existing life cycle impact assessment methods addressing impacts of mineral resource use, covering a broad overview of basic impact mechanisms to a detailed discussion of method-specific modeling. This supports a better understanding of what the methods actually assess and highlights their strengths and limitations. Building on these insights, Berger et al. (Int J Life Cycle Assess, 2020) provide recommendations for application-dependent use of the methods, along with recommendations for further methodological development. [ABSTRACT FROM AUTHOR]

The article characterises the sea-going vessel hull assembly processes and then reviews the existing assembly methods of mechanisms and welded ship structures. Classification of these methods is done with respect to selected criteria of their applicability to hull assembly. Selected methods are used for calculations performed on a model structure and exemplary database. The analysed aspects include the performance of calculation algorithms and the quality of the obtained solutions. Particular attention is paid to the need for reduction of experts' participation in the planning process due to strong search space explosion effect. The performed analyses have enabled the authors to formulate assumptions for models which would be applicable in real assembly planning in shipyards, as well as to indicate areas of further research which would make it possible to better consider the specificity of production of large-size welded structures. [ABSTRACT FROM AUTHOR]

Purpose: In this paper, we summarize the discussion and present the findings of an expert group effort under the umbrella of the United Nations Environment Programme (UNEP)/Society of Environmental Toxicology and Chemistry (SETAC) Life Cycle Initiative proposing natural resources as an Area of Protection (AoP) in Life Cycle Impact Assessment (LCIA). Methods: As a first step, natural resources have been defined for the LCA context with reference to the overall UNEP/SETAC Life Cycle Impact Assessment (LCIA) framework. Second, existing LCIA methods have been reviewed and discussed. The reviewed methods have been evaluated according to the considered type of natural resources and their underlying principles followed (use-to-availability ratios, backup technology approaches, or thermodynamic accounting methods). Results and discussion: There is currently no single LCIA method available that addresses impacts for all natural resource categories, nor do existing methods and models addressing different natural resource categories do so in a consistent way across categories. Exceptions are exergy and solar energy-related methods, which cover the widest range of resource categories. However, these methods do not link exergy consumption to changes in availability or provisioning capacity of a specific natural resource (e.g., mineral, water, land etc.). So far, there is no agreement in the scientific community on the most relevant type of future resource indicators (depletion, increased energy use or cost due to resource extraction, etc.). To address this challenge, a framework based on the concept of stock/fund/flow resources is proposed to identify, across natural resource categories, whether depletion/dissipation (of stocks and funds) or competition (for flows) is the main relevant aspect. Conclusions: An LCIA method-or a set of methods-that consistently address all natural resource categories is needed in order to avoid burden shifting from the impact associated with one resource to the impact associated with another resource. This paper is an important basis for a step forward in the direction of consistently integrating the various natural resources as an Area of Protection into LCA. [ABSTRACT FROM AUTHOR]

Purpose: In recent years, several methods have been developed which propose different freshwater use inventory schemes and impact assessment characterization models considering various cause-effect chain relationships. This work reviewed a multitude of methods and indicators for freshwater use potentially applicable in life cycle assessment (LCA). This review is used as a basis to identify the key elements to build a scientific consensus for operational characterization methods for LCA. Methods: This evaluation builds on the criteria and procedure developed within the International Reference Life Cycle Data System Handbook and has been adapted for the purpose of this project. It therefore includes (1) description of relevant cause-effect chains, (2) definition of criteria to evaluate the existing methods, (3) development of sub-criteria specific to freshwater use, and (4) description and review of existing methods addressing freshwater in LCA. Results and discussion: No single method is available which comprehensively describes all potential impacts derived from freshwater use. However, this review highlights several key findings to design a characterization method encompassing all the impact pathways of the assessment of freshwater use and consumption in life cycle assessment framework as the following: (1) in most of databases and methods, consistent freshwater balances are not reported either because output is not considered or because polluted freshwater is recalculated based on a critical dilution approach; (2) at the midpoint level, most methods are related to water scarcity index and correspond to the methodological choice of an indicator simplified in terms of the number of parameters (scarcity) and freshwater uses (freshwater consumption or freshwater withdrawal) considered. More comprehensive scarcity indices distinguish different freshwater types and functionalities. (3) At the endpoint level, several methods already exist which report results in units compatible with traditional human health and ecosystem quality damage and cover various cause-effect chains, e.g., the decrease of terrestrial biodiversity due to freshwater consumption. (4) Midpoint and endpoint indicators have various levels of spatial differentiation, i.e., generic factors with no differentiation at all, or country, watershed, and grid cell differentiation. Conclusions: Existing databases should be (1) completed with input and output freshwater flow differentiated according to water types based on its origin (surface water, groundwater, and precipitation water stored as soil moisture), (2) regionalized, and (3) if possible, characterized with a set of quality parameters. The assessment of impacts related to freshwater use is possible by assembling methods in a comprehensive methodology to characterize each use adequately. [ABSTRACT FROM AUTHOR]