Functional Causality between Oil Prices and GDP Based on Big Data

This paper examines the causal relationship between oil prices and the Gross Domestic Product (GDP) in the Kingdom of Saudi Arabia. The study is carried out by a data set collected quarterly, by Saudi Arabian Monetary Authority, over a period from 1974 to 2016. We seek how a change in real crude oil price affects the GDP of KSA. Based on a new technique, we treat this data in its continuous path. Precisely, we analyze the causality between these two variables, i.e., oil prices and GDP, by using their yearly curves observed in the four quarters of each year. We discuss the causality in the sense of Granger, which requires the stationarity of the data. Thus, in the first Step, we test the stationarity by using the Monte Carlo test of a functional time series stationarity. Our main goal is treated in the second step, where we use the functional causality idea to model the co-variability between these variables. We show that the two series are not integrated; there is one causality between these two variables. All the statistical analyzes were performed using R software.     

基于图模型方法的Granger因果性检验

Granger因果性是衡量系统变量间动态关系的重要依据.本文利用图模型方法研究变量间的Granger因果性,建立了Granger因果图.基于条件互信息和置换检验法建立了Granger因果图结构的辨识方法,利用混沌理论中的关联积分估计相应的检验统计量,给出了统计量的渐进分布,并用所给方法研究国际主要股市间的Granger因果关系.     

Research output and economic productivity: a Granger causality test

The correlation between GDP and research publications is an important issue in scientometrics. This article provides further empirical evidence connecting revealed comparative advantage in national research with effects on economic productivity. Using quantitative time series analysis, this study attempts to determine the nature of causal relationships between research output and economic productivity. One empirical result is that there is mutual causality between research and economic growth in Asia, whereas in Western countries the causality is much less clear. The results may be of use to underdeveloped nations deciding how to direct their academic investment and industry policy.     

The causal relationship between renewable energy consumption and economic growth: evidence from Europe

The European Union Renewable Energy Directive sets an objective of increasing the renewable energy share of the used renewable energy in the EU by 2020. The objective of this study is to analyze and compare the short-run and long-run relationship between renewable energy consumption and economic growth in 12 European Union countries and to derive implications for renewable energy policy. To do so, we apply panel vector error correction model using the available annual data from 1990 to 2014 on 12 European Union countries. Moreover, Granger causality test is conducted to examine whether there exists any causal linkage between economic growth and renewable energy consumption. The findings indicate the presence of unidirectional causality running from economic growth to renewable energy consumption in the short run. However, in the long run, a bidirectional causal relationship between the variables in question exists.     

The innovation- growth link in OECD countries: Could other macroeconomic variables matter?

This study investigates the Granger causal relationships between innovation, economic growth, information and communication technology (ICT) infrastructure, government consumption expenditure, gross capital formation, foreign direct investment, and trade openness. Using panel data from 32 high-income OECD countries from 1970 to 2016 and panel cointegration techniques, results show that these variables are cointegrated. The Granger causality tests further confirm that, taking other variables into account, there is bi-directional causality between innovation and economic growth in the long run. Moreover, both economic growth and innovation are generally impacted in the long run by the other variables that we consider. The short-run causality results reveal a diverse pattern of short-run adjustment dynamics among the variables including the possibility of feedback among some of them. Important policy implications for sustainable economic growth and higher innovation suggest elevating government consumption expenditure, increasing capital formation, further opening of countries' economies to trade, as well as improving ICT infrastructure.     

专利产出与区域经济增长的动态关联机制分析

运用动态计量经济学的分布滞后模型、单位根检验模型、协整分析模型和Granger因果检验模型,以及专利产出与经济增长数据,对首都区域专利产出与经济增长关联机制进行了动态计量经济实证分析.结果显示:首都地区专利产出与经济增长当前及之后具有两期的关联性,平均来讲,专利产出每增加1%,首都区域经济当年将增长0.4923%,专利产出在3年内共使得经济增长了0.9847%;专利产出增长与GDP增长存在长期稳定的动态均衡关系,但是其对首都地区经济增长促进作用还不够;专利产出是经济增长Granger意义上的原因,但专利产出没有有效地促进首都区域经济增长,二者之间没有形成一种协调互动的反馈机制.     

广东省区域物流与区域经济增长关系的实证研究

根据1978～2009年的广东省年度数据,选取代表区域物流发展水平的3个重要指标,对广东省经济增长与物流业发展之间的关系进行研究。建立VAR模型,运用脉冲响应模型分析经济增长与物流发展间的联动效应,并运用协整理论和Granger因果检验分析经济增长与物流业的长期关系和因果关系。结果表明,广东省物流业与经济增长之间保持着长期协整关系,长期来看,物流业的发展会促进经济增长。广东省经济增长带动了物流业的快速发展,但是,由于物流业仍然处于发展的初期阶段,对经济增长的促进作用还不是很显著。对广东省发展物流业提出了几点建议。     

The influence of scientific research output of academics on economic growth in South Africa: an autoregressive distributed lag (ARDL) application

An increasing number of researchers have recently shown interest in the relationship between economic growth of a country and its research output, measured in scientometric indicators. The answer is not only of theoretical interest but it can also influence the specific policies aimed at the improvement of a country’s research performance. Our paper focuses on this relationship. We argue that research output is a manifestation of the improvement of human capital in the economy. We examine this relationship specifically in South Africa for the period 1980–2008. Using the autoregressive distributed lag method, we investigate the relationship between GDP and the comparative research performance of the country in relation to the rest of the world (the share of South African papers compared to the rest of the world). The relationship is confirmed for individual fields of science (biology and biochemistry, chemistry, material sciences, physics, psychiatry and psychology). The results of this study indicate that in South Africa for the period 1980–2008 the comparative performance of the research output can be considered as a factor affecting the economic growth of the country. Similarly, the results confirm the results of Vinkler (2008) and Lee et al. (2011). In contrast, economic growth did not influence the research output of the country for the same period. Policy implications are also discussed.     

Bootstrapping cointegration tests under structural co-breaks: A robust extended ECM test

The aim of the paper is the analysis of ECM (Error Correction Model) bootstrap cointegration tests under structural breaks. Classical ECM tests depend on some nuisance parameters, which is an undesirable feature for empirical applications. This problem is overcome by using the bootstrap ECM test, which shows good size and power properties when there are no breaks. In this paper we study the small sample properties of alternative bootstrap ECM tests under different co-breaking situations. ECM test statistics are made robust to partial co-breaking by using extended error correction models or by imposing a common factor restriction. The second author acknowledges support from the following grants: Spanish MCyT BEC2002-00279, The European TMR-ERB-40618C97-0994 and the Secretaría de Estado de Universidades PR2002-0305     

Bidirectional relationship between network position and knowledge creation in Scientometrics

Based on the 3100 papers published in the international journal Scientometrics retrieved from Web of Science database over the period 1996–2015, we utilize three-stage least squares (3SLS) to investigate the bidirectional relationship between authors’ network position and knowledge creation. Furthermore, our research is of great benefit to better understanding of the interplay of knowledge and collaboration networks on knowledge creation. The empirical results confirm that the prolific co-authorship and international co-authorship have positive and significant effects on the knowledge creation. The results from the 3SLS estimation models using the number of publications and citations as dependent variables also show that the structural holes of an author in the collaboration networks and her/his knowledge elements in knowledge networks have positive effects on her/his knowledge creation. These findings suggest that structural capital of an author and his/her knowledge elements are important influence factors of the quantity and quality of research output. The results of the models in this paper suggest that authors with better performance in knowledge creation are more likely to attract collaborators and occupy structural holes. In summary, we fill the research gap in exploring the bidirectional relationship between authors’ network positions (in terms of degree centrality and structural holes) and research output.     

我国科技进步对国家标准发展的影响研究

本文以我国1990年～2009年数据为基础,采用协整和因果检验的方法,实证分析了我国的科技进步、研发创新与国家标准之间的关系。结果表明:研发与标准确为因果关系,且加强研发活动对促进国家标准是有积极意义的,其对国家标准的贡献为0.24。     

基于动量动力学模型的行人关系分析

进行了行人行为分析及行人关系研究。考虑到在机器视觉领域大多数研究仅关注于目标行为分类与识别,而目标间因果关系判别研究较少,且现有理论停留在心理学领域中的因果关系表达,提出了一种基于动量动力学模型的目标间因果关系识别方法,用于实现行人间因果关系的识别及量化计算。该方法利用Cam shift算法获得目标在视频中的位置并依据因果概念,构建动量动力模型,然后基于动量动力模型进行因果关系判别,最后计算因果值。根据因果值范围识别出视频行人间的三种因果关系:导致、促进和阻碍。实验表明,上述方法可以在视频监控条件下识别两运动行人间的因果关系。     

Vibration Analysis at Microscale by Talbot Fringe Projection Method1

Abstract: This work focuses on the implementation of a structured light projection technique for the analysis of the 3D vibration modes of microsamples. The Talbot image of a Ronchi grating is projected onto the sample surface passing through one of the objective tube of a stereomicroscope thus realising a fringe projection system at a micrometric scale. An aluminium cantilever beam PZT‐driven into harmonic vibration served as test sample for investigating the possibility to get the full‐field vibration modes of micro‐objects. An automated Fourier transform analysis of the fringe patterns was performed to obtain the full‐field time‐resolved profile information of the sample at each frame delivered by a high‐speed camera with a micrometric resolution. A straightforward procedure for retrieving resonance frequency for different modes and vibration amplitudes along the whole sample surface was implemented. The great sensitivity and the full‐field capacities of the proposed experimental procedure allow to put in evidence differences between real and theoretical behaviours hence could be extremely useful for designing and testing structural dynamic response of microstructures and micro–electro–mechanical Systems.     

Efficient Bootstrap Tests for the Goodness of Fit in Covariance Structure Analysis

Asymptotic chi-square tests, such as the normal theory likelihood ratio test, are often used to evaluate the goodness-of-fit of a covariance structure analysis model. Another approach is to use the bootstrap test, which is known to have the desired asymptotic level if model restrictions are taken into account in designing a resampling algorithm. The bootstrap test is. however, computationally very tedious and the problem of nonconvergence and improper solutions often arise in bootstrap resampling. In this paper, we propose a bootstrap test which is based on an approximation, by a quadratic form, to the minimum value of a discrepancy function calculated from each bootstrap sample. Hence, the proposed bootstrap test is efficient in the sense of the amount of computing needed and is free from the problem of nonconvergence and improper solutions with resampling. A Monte Carlo experiment is conducted to compare the performance of the proposed method with that of asymptotic chi-square tests for each combination of three distributions and four sample sizes.

     

A test of inventory models with permissible delay in payment

Contrary to the long-standing view in the finance literature that firms should maximise payment delays, research in operations management suggests that long payment delays can be suboptimal. In this study, we reconcile these two views by applying a secondary data approach to established operations management theory. Based on a sample of 3383 groups of public US firms from a novel database, we find that our data are consistent with the causal relations and theoretical predictions of the operations management literature. Firm profitability is positively associated with payment delay. Payment delay, in turn, is positively associated with the capital cost difference between buyer and supplier and negatively associated with the price elasticity of demand and the deterioration rate of inventory. However, we do not observe any significant interaction effects between these factors, which raise a number of questions for future research.     

Correlation between the structure of scientific research,scientometric indicators and GDP in EU and non-EU countries

Significant discrepancies were found in the ratio and relative impact of the journal papers of several scientific fields of some Central and Eastern European (CEE) countries compared to the European Community member states, the US and Japan (EUJ countries). A new indicator, characterizing the Mean Structural Difference of scientific fields between countries has been introduced and calculated for CEE countries. For EUJ countries correlation between the GDP and number of publications of a given year proved to be non-significant. Longitudinal studies showed, however, significant correlations between the yearly values of GDP and number of papers published. Studying data referring to consecutive time periods revealed that there is no direct relationship between the GDP and information production of countries. It may be assumed that grants for R&D do not actually depend on real needs, but the fact is that rich countries can afford to spend more whilst poor countries only less money on scientific research.     

Gene regulatory network discovery using pairwise Granger causality

Discovery of gene regulatory network from gene expression data can yield a useful insight to drug development. Among the methods applied to time‐series data, Granger causality (GC) has emerged as a powerful tool with several merits. Since gene expression data usually have a much larger number of genes than time points therefore a full model cannot be applied in a straightforward manner, GC is often applied to genes pairwisely. In this study, the authors first investigate with synthetic data how spurious causalities (false discoveries) may arise because of the use of pairwise rather than full‐model GC detection. Furthermore, spurious causalities may also arise if the order of the vector autoregressive model is not high enough. As a remedy, the authors demonstrate that model validation techniques can effectively reduce the number of false discoveries. Then, they apply pairwise GC with model validation to the real human HeLa cell‐cycle dataset. They find that Akaike information criterion is generally most suitable for determining model order, but precaution should be taken for extremely short time series. With the authors proposed implementation, degree distributions and network hubs are obtained and compared with existing results, giving a new observation that the hubs tend to act as sources rather than receivers of interactions.Inspec keywords: biology computing, cancer, causality, cellular biophysics, genetics, genomics, time seriesOther keywords: gene regulatory network discovery, pairwise Granger causality, gene expression data, drug development, time‐series data, synthetic data, spurious causalities, full‐model Granger causality detection, vector autoregressive model, real human HeLa cell‐cycle dataset, Akaike information criterion, degree distributions, network hubs     

我国科技进步促进地方标准发展的实证研究

本文从技术的角度,研究我国地方标准发展的动力和原因,具体以1990~2009年数据为基础,采用协整和因果检验的方法,实证分析了技术进步对地方标准发展的数量关系。研究结果表明:技术进步对地方标准的发展具有根本性的影响,地方标准是技术发展的结果,增加技术活动的强度会对地方标准数量的增长产生影响。仅考虑单个解释变量,则研发经费的增加对地方标准增长的影响是0.49,如果在双解释变量模型中,专利申请对地方标准的影响已上升到2.9。并且,由于地方标准具有"知识溢出"的特征,研发主体更加愿意"搭便车",更加愿意把成果变为专利,以保护其知识产权。所以,在双变量的模型中,地方标准的变化与专利申请成正向关系,与研发资金成负向关系。这也是符合标准化发展一般规律的。     

Do co-publications with industry lead to higher levels of university technology commercialization activity?

Using the university–industry co-publications (UICP) propensity indicators developed by Tijssen (CWTS Working Paper Series, CWTS-WP-2012-009, 2009), this paper examines the impact of university–industry R&D collaboration on university technology commercialization output for leading US and Canadian universities. Our analysis suggests that UICPs do have a significant positive influence on universities’ technology commercialization outputs, after controlling for the quantity and quality of their research and for their commercialization resources. The results are robust for all three common measures of university technology commercialization: patenting (both in terms of simple patent counts and citation-weighted counts), spin-off formation, and technology licensing. To supplement the aggregate regression findings, five case studies are provided that offer further insights on the causal mechanisms involved. Implications of these findings and possible future research directions are discussed.     

The value of an overseas research trip

As an essential part of the academic environment, international scientific mobility draws considerable attention from researchers. Previous studies have indicated a strong relationship between scientific mobility and scientific output. However, few researchers have addressed the causality between them. The research questions in this study focused on how the international scientific mobilization of the researchers affects their number of international collaborations, their ability to get published at higher impact factor journals, the number of citations that they get. Based on the SCOPUS database of English language scientific journal articles, this paper revealed the causal effects of international scientific mobility of the researchers on their scientific productivity, collaborations, and impact on science using the synthetic control method. The author’s affiliation on their articles provided the geographical location that can be tracked in time to infer the international scientific mobility of each author. A sample of more than 79,000 immobile scientists was used to create the synthetic versions of over 1500 internationally mobile scientists, so that, the synthetic version of each mobile author best resembled the academic ability of her/his counterpart mobile author in the pre-mobilization period. This allowed investigating the effects of the international mobilization on their publications by comparing the post-mobilization publication characteristics of the mobile authors and their immobile synthetic controls.The findings show strong evidence of a substantial positive effect of scientific mobility on the ability to get published in more prestigious journals, the number of citations received in total and from overseas, and international collaborations. The magnitude of the effect is conditional on the duration of scientific mobility.