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1 – 10 of over 12000Maayan Zhitomirsky-Geffet and Judit Bar-Ilan
Ontologies are prone to wide semantic variability due to subjective points of view of their composers. The purpose of this paper is to propose a new approach for maximal…
Abstract
Purpose
Ontologies are prone to wide semantic variability due to subjective points of view of their composers. The purpose of this paper is to propose a new approach for maximal unification of diverse ontologies for controversial domains by their relations.
Design/methodology/approach
Effective matching or unification of multiple ontologies for a specific domain is crucial for the success of many semantic web applications, such as semantic information retrieval and organization, document tagging, summarization and search. To this end, numerous automatic and semi-automatic techniques were proposed in the past decade that attempt to identify similar entities, mostly classes, in diverse ontologies for similar domains. Apparently, matching individual entities cannot result in full integration of ontologies’ semantics without matching their inter-relations with all other-related classes (and instances). However, semantic matching of ontological relations still constitutes a major research challenge. Therefore, in this paper the authors propose a new paradigm for assessment of maximal possible matching and unification of ontological relations. To this end, several unification rules for ontological relations were devised based on ontological reference rules, and lexical and textual entailment. These rules were semi-automatically implemented to extend a given ontology with semantically matching relations from another ontology for a similar domain. Then, the ontologies were unified through these similar pairs of relations. The authors observe that these rules can be also facilitated to reveal the contradictory relations in different ontologies.
Findings
To assess the feasibility of the approach two experiments were conducted with different sets of multiple personal ontologies on controversial domains constructed by trained subjects. The results for about 50 distinct ontology pairs demonstrate a good potential of the methodology for increasing inter-ontology agreement. Furthermore, the authors show that the presented methodology can lead to a complete unification of multiple semantically heterogeneous ontologies.
Research limitations/implications
This is a conceptual study that presents a new approach for semantic unification of ontologies by a devised set of rules along with the initial experimental evidence of its feasibility and effectiveness. However, this methodology has to be fully automatically implemented and tested on a larger dataset in future research.
Practical implications
This result has implication for semantic search, since a richer ontology, comprised of multiple aspects and viewpoints of the domain of knowledge, enhances discoverability and improves search results.
Originality/value
To the best of the knowledge, this is the first study to examine and assess the maximal level of semantic relation-based ontology unification.
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The purpose of this paper is to explore the intricate relationship between the flagship of the sharing economy, Airbnb and hotel revenue per available room (RevPAR) in South…
Abstract
Purpose
The purpose of this paper is to explore the intricate relationship between the flagship of the sharing economy, Airbnb and hotel revenue per available room (RevPAR) in South Africa.
Design/methodology/approach
To identify the impact of Airbnb on hotel RevPAR, the paper used a triple difference-in-differences framework that compares changes in cities in South Africa where Airbnb started operating relative to areas without Airbnb. A total of 569 hotels were analysed.
Findings
While the study finds no evidence of adverse impacts of Airbnb on hotel RevPAR, the findings show that the entry of Airbnb led to a decrease in RevPAR of budget hotels. However, its impact is more pronounced during periods of peak demand, consequently, disrupting the pricing power of hotels.
Research limitations/implications
The research was based on the impact of Airbnb on hotel RevPAR in hotels situated in specific cities in South Africa. Caution is therefore required when generalising the findings of this study to other hotels in other geographic areas. Moreover, if a longer time series data set of hotels in the post-Airbnb time period could become available, it would be interesting to further investigate the time-varying dynamic effects of Airbnb on hotel RevPAR. However, the findings underscore the notion that innovations are not intrinsically disruptive but only relative to another product. In so doing, the study adds to the limited body of work in the field on disruptive innovation and to the academic discourse on innovation in tourism more broadly.
Practical implications
First, the findings suggest the impact on hotels tends towards Airbnb generally playing a largely complementary role rather than a diversionary one. However, to increase RevPAR, hotels should systematically change their pricing models to account for flexible capacity by rethinking the wisdom of seasonal pricing and reduce prices during peak seasons to avoid inviting more competition from Airbnb.
Originality/value
To the best of the author’s knowledge, this paper is the first to explore the relationship between Airbnb and hotel markets using a triple difference methodology.
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Hye-Sung Kim and Christopher J. Marier
Government repression against civilians while enforcing COVID-19 related lockdowns was widely reported in Africa. At the same time, many have claimed that high-speed (4G) mobile…
Abstract
Purpose
Government repression against civilians while enforcing COVID-19 related lockdowns was widely reported in Africa. At the same time, many have claimed that high-speed (4G) mobile network proliferation provide an accountability mechanism that may constrain police abuses. This study focused on Nigeria to examine (1) the effect of COVID-19 lockdowns on police repression and (2) whether widespread high-speed mobile data networks constrain police repression.
Design/methodology/approach
Using data from the Armed Conflict Location and Event Database (ACLED) and the Mobile Coverage Database, this study used difference-in-differences (DID) and triple difference (DDD) estimation on a sample of 423,925 observations (local government area-days) between January 1, 2019 and June 30, 2020 to estimate the causal effects of COVID-19 lockdowns and high-speed (4G) mobile data on police repression.
Findings
Lockdowns increased certain forms of police repression in areas with substantial high-speed (4G) mobile networks. Separate from the lockdowns, widespread 4G network increased police repression even without lockdowns.
Research limitations/implications
Proliferation of high-speed mobile networks in Nigeria appears to facilitate, rather than constrain, police repression. It is possible that high-speed mobile data networks allow police to detect and repress citizen behaviors, rather than permitting citizens to correct repressive police behaviors.
Originality/value
Although many studies have explored the COVID-19 pandemic and police behavior in Western countries, only a few have examined its effects in states with even more troubled policing institutions, including those in sub-Saharan Africa, using DID and DDD estimation.
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Emmanuel Duodu, Eric Fosu Oteng-Abayie, Prince Boakye Frimpong and Paul Owusu Takyi
This study is motivated by the Compact with Africa (CWA) initiative to promote foreign direct investment (FDI) in Africa. However, FDI is argued to be one of the primary causes of…
Abstract
Purpose
This study is motivated by the Compact with Africa (CWA) initiative to promote foreign direct investment (FDI) in Africa. However, FDI is argued to be one of the primary causes of environmental pollution (CO2 emissions). In that regard, this study estimates the impact of the CWA initiative on FDI and environmental pollution.
Design/methodology/approach
The study utilized the difference-in-difference (DID) and triple difference (DDD) estimation strategies to examine the causal impact of the CWA initiative on FDI and environmental pollution from 2005 to 2019. The study selected nine CWA countries and nine non-CWA countries as treatment and control samples.
Findings
The authors found that the CWA initiative positively promotes FDI in the participant countries compared to non-participant countries. The CWA initiative also promoted environmental pollution in the CWA countries compared to non-CWA countries. Furthermore, the DDD estimates show that the effect of the CWA initiative on environmental pollution is through FDI.
Practical implications
The authors recommend policies to attract environmentally friendly FDI for both Compact and non-Compact economies.
Originality/value
The study is the first to provide empirical evidence on the CWA initiative on FDI and environmental pollution in Africa. The study used a quasi-experimental method on the relationship between FDI and environmental pollution in Africa.
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Imen Khanchel and Naima Lassoued
This paper aims to contribute to the literature on the earnings management (EM)–corporate social responsibility (CSR) relationship as most of the previous studies have been…
Abstract
Purpose
This paper aims to contribute to the literature on the earnings management (EM)–corporate social responsibility (CSR) relationship as most of the previous studies have been carried out in non-turbulent periods. This study investigates whether CSR affects EM during the pandemic period by testing two hypotheses: the cognitive biases hypothesis and the resilience hypothesis
Design/methodology/approach
The difference-in-difference and triple difference approaches are used for a sample of 536 US firms (268 socially responsible firms and 268 matched non-socially responsible counterparts) during the 2017–2021 period. Socially responsible firms are selected from the MSCI KLD 400 Social Index, and matched firms are identified through the propensity score matching method.
Findings
The authors find an income-increasing practice for both socially responsible firms and control firms for the whole period and each sub-period. Moreover, socially responsible firms are more likely to manage their earnings (income increasing) than their counterpart. Furthermore, the authors show that CSR commitment exacerbated EM in line with the cognitive biases hypothesis.
Originality/value
This study is the first shed light on the dark side of CSR during pandemic periods.
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Chu-Shiu Li, Chwen-Chi Liu and Yuehua Zhang
The purpose of this paper is to examine the relationship between the purchase of insurance and economic growth among agricultural households.
Abstract
Purpose
The purpose of this paper is to examine the relationship between the purchase of insurance and economic growth among agricultural households.
Design/methodology/approach
Using survey data of the agricultural sector obtained from China over two years, the authors highlight the effect of job switching between farm and non-farm activities on the demand for insurance by applying the difference-in-differences and triple differences methodologies.
Findings
The results show that compared with farm income, non-farm income is associated with an increased (decreased) demand for insurance among households in Eastern (Western) China. The inequality in degree of economic development between the regions plays an important role in this finding. Both education and income exhibit a positive relationship with insurance demand for most regions. In addition, in 2007, regardless of farm or non-farm sector, switches are (except in the northeast region) associated with a significant increase in insurance expenditures. Households who switched from the farm to non-farm sector in 2007 are significantly negatively associated with insurance expenditures in the western region.
Social implications
Inequalities in the degree of economic development play an important role in insurance consumption.
Originality/value
The authors assess the determinants of insurance market development in the agricultural sector in China, characterized by inter-regional disparities in economic development.
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Jing Wang and Morley Gunderson
The purpose of this paper is to estimate the causal effect of minimum wages on the employment of low-skilled workers in less developed regions of China.
Abstract
Purpose
The purpose of this paper is to estimate the causal effect of minimum wages on the employment of low-skilled workers in less developed regions of China.
Design/methodology/approach
Based on data from the China Health and Nutrition Survey, a double-difference (DD) methodology is used to compare the employment of low-skilled individuals before and after a minimum wage increase in their provinces with a comparison group of individuals in provinces that did not have a minimum wage increase. Also, a triple-difference methodology (DDD) is used that also includes an additional control group of highly educated workers as a within-province internal comparison group that should not be affected by a minimum wage increase.
Findings
No evidence of an adverse employment effect is found in any of the 36 different estimates, consistent with recent US evidence that uses a similar DD methodology.
Research limitations/implications
The data are not national representative; rather heavily weighted towards the less developed Central, Western and parts of the Eastern Regions of China. This may partially explain the absence of the theoretically expected adverse employment effect. Other related reasons are discussed, including: lack of enforcement in those less developed regions; a large presence of state-owned enterprises in the regions where employment security clause remains intact; the relatively less developed labour markets in the regions including where employers may behave in a monopsony fashion in their labour markets; shock effects; and cost offsets from reduced fringe benefits and increases in the pace of work. This paper was unable to disentangle the separate effect of these possible factors.
Originality/value
This is one of the few studies on minimum wages in China to focus on low-skilled workers in less developed regions, to use individuals as the unit of observation rather than aggregates, and to provide causal estimates based on DD and DDD methodologies.
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Xu He and Takeshi Sakurai
Total farmland value exceeds its value in agriculture but is not directly perceptible to villagers in China. Thus, the exceeded part is often neglected when discussing farmer’s…
Abstract
Purpose
Total farmland value exceeds its value in agriculture but is not directly perceptible to villagers in China. Thus, the exceeded part is often neglected when discussing farmer’s land transaction decision. This study aims to revisit the question about how land titling project affects farmer’s land renting-out and investigate how this unobservable land value would distort the intentional effects of land titling.
Design/methodology/approach
This paper first modifies a two-period model by incorporating the unobservable part of land value into the farmers’ leasing decision problem. Following the implications from the theoretical analysis, this study then exploits the difference-in-differences and the triple-differences approach to confirm the distorting effects that are resulted from the unobservable land value.
Findings
The modified theoretical model of this study reveals that land titling would encourage farmers to rent out land when the unobservable land value is predicted to be low but discourage farmers’ willingness to rent-out when this value is predicted to be high. The core reason for this significant conclusion lands in the uncertainty of the unobservable land value. Empirical analysis then provided two evidences for this presumption. Furthermore, this study also gave a disproof of the argument that the uncovered discouraging effect is due to a stronger endowment effect.
Originality/value
This paper contributes to the literature by highlighting the unobservable land value in the farmers’ land-related decisions. This part of land value is always neglected in previous discussions about the land tenure system, but it would cause distorting effects especially in regions without private land ownership.
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The purpose of this review article is to demonstrate how the quasi-experimental approach has been used to study environmental and natural resource issues related to agricultural…
Abstract
Purpose
The purpose of this review article is to demonstrate how the quasi-experimental approach has been used to study environmental and natural resource issues related to agricultural production.
Design/methodology/approach
This review article first provides a short introduction to the quasi-experimental approach using the potential outcomes framework and then uses studies on the environmental sustainability of agricultural production to illustrate how quasi-experimental methods have been applied. Papers reviewed consist of studies that estimate the environmental externalities from agricultural production, evaluate agri-environmental and other related policies and programs, and demonstrate issues related to on-farm resource use and climate adaptation.
Findings
Difference-in-differences (DID) and two-way fixed effects methods that utilize the spatial and temporal variation in panel data are widely used to estimate the causal impact of changes in agricultural production and policy on the environment. Utilizing the discontinuities and limits created by agricultural policies and regulations, local treatment effects on land and other input use are estimated using regression discontinuity (RD) or instrumental variable (IV) methods with cross-sectional data.
Originality/value
Challenges faced by the food systems have made agricultural sustainability more critical than ever. Over the past three decades, the quasi-experimental approach has become the powerhouse of applied economic research. This review article focuses on quasi-experimental studies on the environmental sustainability of agriculture to provide methodological insights and to highlight gaps in the economics literature of agricultural sustainability.
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This chapter reviews the existing empirical evidence on how social insurance affects health. Social insurance encompasses programs primarily designed to insure against health…
Abstract
This chapter reviews the existing empirical evidence on how social insurance affects health. Social insurance encompasses programs primarily designed to insure against health risks, such as health insurance, sick leave insurance, accident insurance, long-term care insurance, and disability insurance as well as other programs, such as unemployment insurance, pension insurance, and country-specific social insurance programs. These insurance systems exist in almost all developed countries around the world. This chapter discusses the state-of-the art evidence on each of these social insurance systems, briefly reviews the empirical methods for identifying causal effects, and examines possible limitations to these methods. The findings reveal robust and rich evidence on first-stage behavioral responses (“moral hazard”) to changes in insurance coverage. Surprisingly, evidence on how changes in coverage impact beneficiaries’ health is scant and inconclusive. This lack of identified causal health effects is directly related to limitations on how human health is typically measured, limitations on the empirical approaches, and a paucity of administrative panel data spanning long-time horizons. Future research must be conducted to fill these gaps. Of particular importance is evidence on how these social insurance systems interact and affect human health over the life cycle.
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