Showing papers in "Economic Computation and Economic Cybernetics Studies and Research in 2018"
TL;DR: In this paper, the rank reversal phenomenon was analyzed in a new MCDM method called EDAS (Evaluation based on Distance from Average Solution), and the efficiency of the EDAS method was compared with the TOPSIS method through a simulation-based analysis.
Abstract: The rank reversal (RR) phenomenon could occur when new information about alternatives or criteria is added to the decision space of a discrete multi-criteria decision-making (MCDM) problem. If this addition leads to a change in the original rank of alternatives, the RR phenomenon occurs. In this study, we analyze the RR phenomenon in a new MCDM method called EDAS (Evaluation based on Distance from Average Solution). For this purpose, three RR indices are defined, and the efficiency of the EDAS method is compared with the TOPSIS method through a simulation-based analysis. The results show that the EDAS method is more efficient than the TOPSIS method with respect to the defined RR measures.
44 citations
TL;DR: It has been established that supplier A6 shows the best results in relation to other suppliers, and this results were confirmed by sensitivity analysis.
Abstract: Today, there is strong competition in the market, and therefore an adequate process of selecting suppliers, as one of the key activities in the supply chain management, can contribute to the company's overall business. In an empirical research that dealt with the selection of suppliers for a paper manufacturing company, it was necessary to select a supplier that would contribute to improving the environmental awareness of this company. The selection of suppliers in this paper is based on the application of the interval fuzzy logic and the group decision making model. Interval fuzzy logic was applied to the AHP and TOPSIS methods. The AHP method has determined the weights of the criteria, while TOPSIS method ranks the supplier based on the distance from an ideally positive and negative solution. Linguistic values were used to meet the criteria of supplier. Based on a practical example conducted on real suppliers, it has been established that supplier A6 shows the best results in relation to other suppliers. These results were confirmed by sensitivity analysis.
21 citations
TL;DR: The TBATS model as mentioned in this paper has no seasonality constraints, making it possible to create detailed, long-term forecasts for time series forecasting, which has been shown to outperform other popular models such as ARIMA and exponential smoothing.
Abstract: Many researchers are familiar with time series forecasting, yet they struggle with specific types of data that require a suitable model of analysis. One such type of data might be seasonality. However, one has to note that most popular models (e.g. ARIMA and exponential smoothing) only account for one seasonality. This article presents the capabilities of the TBATS model which has no seasonality constraints, making it possible to create detailed, long-term forecasts.
19 citations
TL;DR: In this article, the authors provided an empirical evaluation of the tax effects on economic growth in 35 OECD countries from 1996 to 2016, where analysis involves gross domestic product as a proxy for economic growth.
Abstract: The research paper provides an empirical evaluation of the tax effects on economic growth in 35 OECD countries from 1996 to 2016. The objective of this paper is to find how taxes effect on the economy, where analysis involves gross domestic product as a proxy for economic growth. Ensuring fundamental econometric procedures, the research paper reflects fixed effect model which measure the impact of tax revenue growth, personal income tax, corporate income tax, social security contributions, tax on goods and services and tax on property on dependent variable as a gross domestic product. The analysis includes main macroeconomic determinants as an inflation, unemployment, government expenditure and investment in observed countries. Results show that 1% increase of tax revenue growth enhances the gross domestic product for 0.29% which is confirmed previous studies that manifested significant and positive relationship between these variables. Further, there is recorded the significant and positive effect of tax on property on economic growth, where 1% increase of this tax form raises a gross domestic product for 0.21%. On the contrary, tax on goods and services have a harmful effect on economic growth, where 1% increase of them cause gross domestic product drop of 0.60%, which is statistically significant.
18 citations
15 citations
TL;DR: None of the 5 methods were the best or the worst in all cases, Nevertheless, Minmax method in most cases is significantly better than other and Log method in some cases is the worst but it is the best (or one of the best) in other cases.
Abstract: One of the most important stages of solving MCDM problems is normalization of initial decision-making matrix. The impact of 5 widely used normalization methods on the best alternative determination accuracy in the case of ternary estimates decision matrix is analysed in the article. Alternatives ranked by applying SAW method. Monte Carlo procedure was conducted fordata matrices of different dimensions and both optimization directions. Two cases the more and the less separable alternativeswere analysed.None of the 5 methods were the best or the worst in all cases. Nevertheless, Minmax method inmost cases is significantly better than other. The Log method is the worst in some cases, but it is the best (or one of the best) in other cases.The highest values of the best alternative detection accuracy were accompanied by the lowest standard deviations of experiment results, respectively, the lowest values – by the highest standard deviations.
14 citations
TL;DR: In this article, the identification of developments of the circular economy in Romania under the new sustainability paradigm using econometric methods was investigated, and the construction of a model that adequately reflects the transformations generated by the process of transition to the circular economic in Romania was considered.
Abstract: The transformation of the functional and highly competitive contemporary market economy paradigm and of the established economic structures has imposed the orientation and adoption of innovative, high-yielding and environmentally sustainable economic models, capable of generating both elevated levels of economic well-being and social protection. The multiplication and diversification of contemporary economic, social and environmental challenges forced important transformations of the economic paradigm. The limitations of the classic linear economic system have generated the emergence of new contemporary economic models, most often of hybrid type, which have significantly contributed to the conversion of classical production and consumption relations. The main objective pursued in this research is the identification of developments of the circular economy in Romania under the new sustainability paradigm using econometric methods. At the same time, the construction of an econometric model that adequately reflects the transformations generated by the process of transition to the circular economy in Romania was considered.
14 citations
TL;DR: In this paper, the correlation among economic policy uncertainty (EPU)indices of eight countries in European Union (EU) from March 2003 to January 2017 is studied by using grey relational analysis (GRA).
Abstract: To estimate the mutual effect of economic policy among European countries, the correlation among economic policy uncertainty (EPU)indices of eight countries in European Union (EU) from March 2003 to January 2017 is studied by using grey relational analysis (GRA). The result shows that under the framework of European economic integration, grey relational degree of EPU of European countries are all above 0.8, which reflects a strong economic policy co-movement of EU countries. The EPU indices of the UK and France with large economic mass are hardly influenced by other countries, which indicate that the economic policy influences of the two countries are larger than those of other countries. Additionally, due to the influence of exiting from the EU, the UK exhibits the lowest and dramatically fluctuating economic policy correlation with the other countries in recent years.
13 citations
13 citations
TL;DR: In this paper, the principal worth-creating activities for social economy companies that dedicate their activities to the service sector of the Balearic Islands were analyzed and both direct and second generation causes that arise in the majority of the socioeconomic cases were identified.
Abstract: Few studies have analyzed how to improve the results and productivity of companies with very peculiar characteristics, such as social economy entities. This paper determines the principal worth-creating activities for this type of companies that dedicate their activities to the service sector of the Balearic Islands. In order to carry out this work, incidence matrixes and recovery of forgotten effects have been used. Both direct cause and second generation causes that arise in the majority of the socio-economic cases have been identified. In fact, determining the second generation effects, or forgotten effects, is one of the main contributions of this study as it shows that those causes that are usually not foreseen, at least in the first instance, affect notably in the generation of social economy companies value to the service sector of the Balearic Islands.
11 citations
TL;DR: It is shown that the regularized functional of the game decreases and converges, proving the existence and uniqueness of strong Nash equilibrium.
Abstract: This paper suggests a novel cooperative game-theoretic approach to solve the transfer pricing problem for a multidivisional firm considering that each division purchases goods from an upstream division in the supply chain. The formulation of the transfer pricing problem considers costs and taxes in a vertically integrated supply chain. We conceptualize the transfer pricing as a multi-objective problem and present a method for finding the strong Nash equilibrium that maximizes the utility of the entire multidivisional firm. The approach consists on determining a scalar and the corresponding strategies ) ( v fixing specific bounds on the Pareto front. Bounds correspond to restrictions imposed by each division over the Pareto front that determine the maximum and minimum transfer price legally authorized. For ensuring the existence of a unique strong Nash equilibrium, we employ a penalized regularization method for poly-linear functions. We implement a recurrent procedure for finding the extremal point. For finding the strong Nash equilibrium, we select the Pareto optimal strong strategy ) ( v with minimal distance to the utopia point. We show that the regularized functional of the game decreases and converges, proving the existence and uniqueness of strong Nash equilibrium. The usefulness of the method is successfully demonstrated by a numerical example.
TL;DR: In this paper, a mathematical model for the cyclicality of the price evolution is presented, which can be applied for any equity in any financial market, using any timeframe and can give us information about when is good to buy and when is better to sell.
Abstract: Trading the financial markets is a common idea nowadays. Millions of market participants, individuals, companies or public funds are buying and selling different equities in order to obtain profit from the buy and sell price difference. Once the equity was established, the main question marks are when to buy, when to sell and how long to keep the opened positions. This paper will present a mathematical model for the cyclicality of the price evolution. The model can be applied for any equity in any financial market, using any timeframe. The method will gives us information about when is good to buy and when is better to sell. The price cyclicality model is also a method to establish when the price is approaching to change its behavior in order to build limit conditions to stay away the market and to minimize the risk. The fundamental news is already included in the price behavior. Being exclusively a mathematical model based on the price evolution, this method can be easily implemented in algorithmic trading. The paper will also reveal how the cyclicality model can be applied in automated trading systems and will present comparative results obtained in real-time trading environment.
TL;DR: In this article, the second-generation cointegration test and the Dumitrescu and Hurlin (DH) heterogeneous panel Granger causality test over the period from 1970 to 2016 were employed to examine the effect of financial instability, energy prices and trade openness on economic growth for leading African countries.
Abstract: This study aimed to examine the effect of financial instability, energy prices and trade openness on economic growth for leading African countries (Egypt, Kenya, Morocco, Nigeria and South Africa). We employed the second-generation cointegration test and the Dumitrescu and Hurlin (DH) heterogeneous panel Granger causality test over the period from 1970 to 2016. The result of cointegration analysis revealed that, there is the existence of a cointegration relationship between the financial instability, oil prices, and trade openness on economic growth sustainability for leading African countries. While, the causality test has revealed a unidirectional causal relationship, which running from financial instability to real economic growth, oil price to real economic growth; and a bidirectional causality running between trade openness and economic growth. The empirical results also showed that, the intervention by leading African country's policymakers could create rigidity or financial repression policies rather than a more stable financial system which could achieve by financial rules and regulations being designed to widen the space for the growth and stability of oriented macroeconomic policies.
TL;DR: In this article, the authors investigated the impact on FDI of different factors, at quarterly and annual frequency, as reflected by economic variables (GDP, labour cost), market variables indicating country risk perception (equity markets volatility, CDS), economic sentiment and confidence indicators (computed by the European Commission) and investor perception indicators (various measures of transparency, public sector governance and accountability, political stability, law enforcement and control of corruption computed by the World Bank).
Abstract: In this paper we have investigated the impact on FDI of different factors, at quarterly and annual frequency, as reflected by economic variables (GDP, labour cost), market variables indicating country risk perception (equity markets volatility, CDS), economic sentiment and confidence indicators (computed by the European Commission) and investor perception indicators (various measures of transparency, public sector governance and accountability, political stability, law enforcement and control of corruption computed by the World Bank). Our analysis was done for ten developing European economies, using a stepwise panel regression approach and a one-lag panel VAR. Our main results confirm the effect of GDP and labour cost on Net FDI that were also identified previously. Also, we found a significant influence from CDS prices, which is aligned with previous findings on the influence of credit ratings. At the same time, our results showed a statistically significant influence on FDI from Voice and Accountability, Government Effectiveness, Regulatory Quality and Control of Corruption.
TL;DR: In this paper, the authors investigated Romanian territorial capital components and analyzed the relationship between them and economic growth using structural equation modeling methodology (SEM) using the available dataset across Romanian counties (NUTS 3) offered by national statistics.
Abstract: The paper investigates Romanian territorial capital components and analyses the relationship between them and economic growth using structural equation modeling methodology (SEM). The available dataset across Romanian counties (NUTS 3) offered by national statistics allows for identifying five components of territorial capital: economic, infrastructural, institutional, human and social capital. Our research reveals that four components economic, infrastructural, institutional and human capital are contributing positively to the Romanian territorial capital and one social capital has a negative impact. Also, we found that not all the components of the Romanian territorial capital positively influenced economic growth. The findings document a positive impact of economic and infrastructural capital, a negative impact of social capital and an insignificant impact of human capital and institutional capital on economic growth. In our opinion, all these findings have important development policy implications and urging for future research.
TL;DR: Simulation results show that the GA-SVR-GM and GA-BPNN-GM consistently have the minimum statistical error of the root mean square error (RMSE), mean absolute error (MAE), and mean absolute percentage error (MAPE) which means that such improving methods are effective.
Abstract: Stock price index (SPI) prediction is essential to investors when they make investment decisions. However, due to the intrinsic complexity and non-stationary of SPI, accurate SPI prediction has been a challenge task for a longtime. Compared to a quantity of single algorithms, hybrid methods always have higher prediction accuracy. Based on the theories of genetic algorithm (GA), grey model (GM), back-propagation neural network (BPNN) and support vector regression (SVR), in this paper, two hybrid models named GA-SVR-GM and GABPNN-GM are proposed for improving the prediction accuracy of Composite Index in Shanghai Stock Exchange (SHSE) and Component Index in Shenzhen Stock Exchange (SZSE). The SVR (or BPNN) is first used to forecast SPI and then with the obtained errors GM is constructed taking into account the different patterns that the SVR (or BPNN) cannot identify, reducing with the final errors. Moreover, in order to obtain the better forecasting results of SVR (or BPNN), the model parameters are optimized by GA. Two prediction cases of SPI are used to test the performance of the proposed hybrid models. Compared with the random walk (RW), SVR, and BPNN, the simulation results show that the GA-SVR-GM and GA-BPNN-GM consistently have the minimum statistical error of the root mean square error (RMSE), mean absolute error (MAE), and mean absolute percentage error (MAPE). Thus, it can be concluded that such improving methods are effective.
TL;DR: In this paper, the authors present the results of a quantitative marketing research (part of a larger qualitative and quantitative research) which was designed in order to identify if and how the online social networks influence the consumers' buying behavior.
Abstract: The emergence of the online social networks (OSN) has created for companies and marketing specialists a brand new method of reaching and communicating with their target groups. This paper aims to present the results of a quantitative marketing research (part of a larger qualitative and quantitative marketing research) which was designed in order to identify if and how the online social networks influence the consumers’ buying behaviour. We presented a short literature review regarding the concepts of online social networks, consumer behaviour, economic and marketing models as well as several marketing models linked to the usage of information technology by the consumers. The second part of our paper presents the research methodology, the proposed conceptual model of online social networks influences on the purchasing behaviour and the validation process. We have shown, following the statistical analysis, that the online social networks influence in certain aspects the buying behaviour of the consumers. We concluded by underlining certain theoretical and managerial implications, as well as by drawing some conclusions and pointing out several research limits.
TL;DR: In this article, the authors study the validity of Okun's law for Slovenia at the national and regional level applying panel data and find that it is valid for Slovenia and 6 out of 12 of its regions.
Abstract: This paper aims to study the validity of Okun ́s law for Slovenia at the national and regional level applying panel data. Different panel data and panel-time series model estimators are applied to test the sensitivity of results to the issues of heterogeneity, cross-section dependence, and endogeneity of regressors. We find that Okun ́s law is valid for Slovenia and 6 out of 12 of its regions. The results imply that all major issues listed in the time-series panel literature should be addressed when estimating Okun ́s coefficient with panel data.
TL;DR: In this paper, a new multi-product multi-stage production planning model is presented, where the demand and delivery time are considered to be uncertain and a robust optimization model with a description of the scenario of uncertainty data has been used.
Abstract: Production planning in the uncertainty conditions is one of the inherent characteristics of manufacturing environments. In this paper, a new multi-product multi-stage production planning model is presented. The demand and delivery time are considered to be uncertain. In order to deal with non-deterministic parameters and reduce their impact on optimal solution, a robust optimization model with a description of the scenario of uncertainty data has been used. The objective is to minimize the cost over the planning horizon. To solve the proposed model, The Branch and Bound (B&B) method is used by using Lingo software.
TL;DR: In this paper, the authors assess the Brexit spillovers upon ten EU economies (EU-10), through labour mobility, as a core pillar of regional integration, and develop two scenarios on the outputs obtained by EU-10related to GDP growth and labour market main results both for natives and the foreign population under the effects of labour and humanitarian immigration flows framed within the Brexit context (2000-2019).
Abstract: This research aims to assess the Brexit spillovers upon ten EU economies (EU-10), through labour mobility, as a core pillar of regional integration. In this regard, we have developed two scenarios on the outputs obtained by EU-10related to GDP growth and labour market main results both for natives and the foreign population under the effects of labour and humanitarian immigration flows framed within the Brexit context (2000-2019). We have built up a panel consisting of representative indicators that have been standardised in order to ensure accurate results for the specific macro-econometric and structural equations models(SEM) applied. The results highlight that the EU-10 will be positively influenced by immigration considering the labour market outcomes, as revealed by important employment levels increases, even though the impact largely differs across countries, under a compelling spatial presence.
TL;DR: In this paper, the authors developed a fast and simplified approach to computing IV egalitarian Shapley values for such a rather large subclass of interval-valued (IV) cooperative games, through adding some weaker coalition monotonicity-like conditions, it is proven that the equality Shapley value is monotonic and non-decreasing.
Abstract: There are not effective and practical methods for interval-valued (IV) cooperative games due to the invertible interval subtraction. This paper focuses on developing a fast and simplified approach to computing IV egalitarian Shapley values for such a rather large subclass of IV cooperative games. In this method, through adding some weaker coalition monotonicity-like conditions, it is proven that egalitarian Shapley value is monotonic and non-decreasing. Hence, the IV egalitarian Shapley value of IV cooperative games can be directly obtained by determining its lower and upper bounds, respectively. The method proposed in this paper does not use the Moore’s interval subtraction and hereby can effectively avoid the issues resulted from it. Furthermore, some important properties of the IV egalitarian Shapley values of IV cooperative games are discussed. The feasibility and applicability of the method proposed in this paper are illustrated with real numerical examples.
Abstract: The influence of health status on labour market behaviour is a subject which has benefited of a wide empirical work so far. And the common finding of positive effects of a good health on labour market participation, productivity and wages has been supported by strong evidence. On the other hand, the inverse relationship the effect of labour market participation on health status -has been less studied. Moreover, the issue has benefited of little attention in Romania. Our paper explores the bidirectional relationship between self-perceived health and labour market outcomes in Romania using a simultaneous equations model. We use EU-SILC data for Romania, the sample being representative for the whole population and consisting of approximately 17 thousand of individuals aged 16 and more. We find that health has a positive influence on labour market participation and incomes, but labour market participation has an adverse effect on health. The results show that individuals do not underreport their health status to justify non-participation. In conclusion, health is endogenous to labour market participation and should be treated as so, otherwise the effects of health on labour market status could be underestimated.