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1.
Previous research studies the age profile of patent citations to learn about knowledge flows over time. However, identification is problematic because of the collinearity between application year, citation year, and patent age. We show empirically that a patent's ‘citation clock’ does not start until it issues, and propose a highly flexible identification strategy that uses the lag between application and grant as a source of exogenous variation. We examine the potential bias if our assumptions are incorrect, and discuss extensions into other research areas. Finally, we use our method to re‐examine prior results on citation age profiles of patents from different technological fields and application year cohorts. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

2.
In this paper, we answer the question why statistics journals get lower impact factors than journals in other disciplines. We analyze diffusion patterns of papers in several journals in various academic fields. To obtain insights into the diffusion of the citation counts of the papers, the data are analysed with the Bass model, leading to values for the time-to-peak that can be used to compare the speeds of diffusion paper citations of the different disciplines. Estimation results show that for statistics journals, it takes significantly more years to reach their peak. To further investigate diffusion, we also compute the percentages of the total number of citations a paper has after 2 or 3 years. Again, it appears that statistics journals have slower citation diffusion than journals in other disciplines. We conclude with some suggestions to reduce this disparity.  相似文献   

3.
Cognitive skills are robustly associated with good national economic performance. How much of this is due to high-skill countries doing a better job of absorbing total factor productivity from the world's technology leader? Following Benhabib and Spiegel (Handbook of Economic Growth, 2005), who estimated the Nelson–Phelps technology diffusion model, I use the database of IQ tests assembled by Lynn and Vanhanen, 2002, Lynn and Vanhanen, 2006 and find a robust relationship between national average IQ and total factor productivity growth. Controlling for IQ, years of education is of modest statistical significance. If IQ gaps between countries persist and model parameters remain stable, TFP levels are forecasted to sharply diverge, creating a “twin peaks” result. After controlling for IQ, few other growth variables are statistically significant.  相似文献   

4.
Wind power technology is analyzed in terms of diffusion, with incentive effects introduced as exogenous dynamics in the Generalized Bass Model (GBM) framework. Estimates and short-term forecasts of the life-cycles of wind power are provided for the US and Europe, as they have similar geographic areas, as well as for some leading European countries. GBMs have the best performance in model selection, and are ranked first in terms of forecast accuracy over a set of different accuracy measures and forecasting horizons, relative to the Standard Bass, Logistic, and Gompertz models.  相似文献   

5.
Weibo, China’s largest microblogging platform, has become one of the key information-sharing platforms in modern society. This study examines topic propagation in relation to microblogging from the perspective of the “peer effect.” Using data of hot topics from Weibo, we analyze how the social effect and propagation pathway influence the topic propagation process. We propose a spatial and temporal heterogeneity diffusion model that includes endogenous and exogenous social effects and is based on but different from the Bass diffusion model. We find that most propagation pathways end after a single level of propagation. The endogenous social effect in microblogs primarily influences the inflow of topics. Such endogenous social effect, combined with the multiplier effect, motivates most users to share a microblog topic in a short period of time. The exogenous social effect primarily influences the outflow of topics, and therefore, the microblog topics of a small number of popular users’ account for most of the share volume. Our results are robust to potential serial correlation, reflection problem, and potential self-selection due to user status.The findings reveal that group characteristics affect individuals’ behaviors and choices in relation to the topic propagation process on microblogging platforms. The use of a spatial and temporal heterogeneity diffusion model and the robustness of the analysis process provide new information for scholars in this field.  相似文献   

6.
In a recent study, Scaglione et al. (2015) analyzed the diffusion of mobile social networking in four G7 countries. Using Bass’s model and Bemmaor’s Gamma/Shifted Gompertz (G/SG) model, they found evidence of a left skew in the right-censored distributions of the times to adoption in three countries out of four. However, this conclusion relied on the skewness parameter of Bemmaor’s model. We reanalyze the data, making use of three special cases of the G/SG as well as the full version. Extending the data set to six countries, we show that (i) fitting the four models to the data does not allow us to discriminate between models, but (ii) forecasting the subsequent adoptions provides a strong support of right skewness in the data set: each country (except France) shows a substantial mass of later adopters of mobile social networking following an initial embrace of the access.  相似文献   

7.
This paper illustrates that salient features of a panel of time series of annual citations can be captured by a Bass type diffusion model. We put forward an extended version of this diffusion model, where we consider the relation between key characteristics of the diffusion process and features of the articles. More specifically, parameters measuring citations’ ceiling and the timing of peak citations are correlated with specific features of the articles like the number of pages and the number of authors. Our approach amounts to a multi-level non-linear regression for a panel of time series. We illustrate our model for citations to articles that were published in Econometrica and the Journal of Econometrics. Amongst other things, we find that more references lead to more citations and that for the Journal of Econometrics peak citations of more recent articles tend to occur later.  相似文献   

8.
The circular economy (CE), definable as a system focused on the reorganization of material, information, and energy flows to achieve greater resource efficiency through the reuse, remanufacturing, and recycling of materials, is a concept widely discussed by practitioners and scientists of many disciplines. Waste recycling is integral to the CE, but there are still few articles focused on waste, and only few studies shed light on CE implementation at the company level. This paper focuses on a particular type of waste, that is, absorbent hygiene products (AHPs), which represents a nonnegligible fraction of municipal solid waste, considered an increasingly serious global challenge. We conducted our analysis on FaterSMART, an Italian firm that developed a unique worldwide technology able to totally convert AHP raw material wastes into recyclable materials, under a CE approach. The case study findings are based upon semi-structured interviews, direct observations, and analysis of FaterSMART's archival documents and are analyzed according to a framework developed for the research and focused on the place of waste from a linear economy, in which waste is considered a burden to CE, in which waste is considered a resource. The latter case is what we found that happens at FaterSMART. FaterSMART's findings could contribute to open up new management scenarios and stimulate further research into how this and similar types of technology will help societies to change from the “use-it-once-and-throw-it away” mentality of linear business models to the sustainable CE model that fully conceptualize waste as a resource for the system.  相似文献   

9.
“Although American higher education can justifiably take pride in its capacity to develop the student's ability to manipulate the material world through its programs in science, medicine, technology, and commerce, it has paid relatively little attention to the student's “inner” development—the sphere of values and beliefs, emotional maturity, moral development, spirituality, and self‐understanding.” —from the Foreword to Encouraging Authenticity and Spirituality in Higher Education by Alexander W. Astin and Helen S. Astin  相似文献   

10.
The determinants of countries' long‐term income differences feature prominently in the literature. Spolaore and Wacziarg (The diffusion of development, Quarterly Journal of Economics, 2009 , 124, 469–529) argue that cultural differences, measured by countries' genetic distance, are an important barrier to the diffusion of development from the world's technological frontier. We revisit their findings in three ways. First, we successfully reproduce their results and confirm the robustness of their baseline findings. Second, we estimate their models for different time periods and find that the impact of genetic distance on income differences did not significantly change over time. Finally, we explore one of the underlying mechanisms of technology adoption and show that bilateral trade is one channel through which cultural differences retard the diffusion of development.  相似文献   

11.
Examination of the spatial diffusion patterns of a sample of 43 technological innovations organized into four functional areas—fire fighting, traffic control, air pollution control, solid waste collection, and disposal—indicates the absence of systematic patterns of either rank-size or contagious diffusion of these innovations among municipal governments in the United States. Absence of these general patterns reflects an inadequate identification in existing theories of spatial diffusion processes of variables that enter into agency decisions to adopt new technologies and the inadequate identification of possible interactions among variables. In particular, attempts to model diffusion patterns based on neighborhood effect or on hierarchical relationships fail to take into account, it least for the classes of adopters and innovations studied here, polynuclear propagation and the role of intermediaries (e.g. professional associations, governmental agencies, suppliers) in communication patterns or the role of site-specific factors that determine the “suitability” or “worth” or an innovation to different potential adopters.  相似文献   

12.
“Although American higher education can justifiably take pride in its capacity to develop the student's ability to manipulate the material world through its programs in science, medicine, technology, and commerce, it has paid relatively little attention to the student's “inner” development—the sphere of values and beliefs, emotional maturity, moral development, spirituality, and self‐understanding.” —from the Foreword to Encouraging Authenticity and Spirituality in Higher Education by Alexander W. Astin and Helen S. Astin  相似文献   

13.
Symposium     
“Although American higher education can justifiably take pride in its capacity to develop the student's ability to manipulate the material world through its programs in science, medicine, technology, and commerce, it has paid relatively little attention to the student's “inner” development—the sphere of values and beliefs, emotional maturity, moral development, spirituality, and self‐understanding.” —from the Foreword to Encouraging Authenticity and Spirituality in Higher Education by Alexander W. Astin and Helen S. Astin  相似文献   

14.
This paper traces the development of ever more microscopic analyses of the industrial innovation process and presents these as progressive stages in a gradual coming to terms with the real-life complexities of this process. Begining with the macroscopic, diffusion perspective inherited from rural sociology, it reveals how more user-centred models have emerged. The changing image of the user is traced from “passive adopter” to “managerial problem solver” and finally, to “innovative designer”. The paper then turns to the difficulties involved in understanding the nature of the firm's infrastructure and the implications it has for innovation management and industrial relations problems. Research in this area is identified as a crucial source of the new management tachniques that are required to solve the growing problems of resistance to technology implementation. A socio-psychological analysis drawing upon the concepts of the ethogenic approach is proposed and seen to recommend a participative management style similar to that used so successfully by the Japanese.  相似文献   

15.
“Although American higher education can justifiably take pride in its capacity to develop the student's ability to manipulate the material world through its programs in science, medicine, technology, and commerce, it has paid relatively little attention to the student's “inner” development—the sphere of values and beliefs, emotional maturity, moral development, spirituality, and self‐understanding.” —from the Foreword to Encouraging Authenticity and Spirituality in Higher Education by Alexander W. Astin and Helen S. Astin  相似文献   

16.
“Although American higher education can justifiably take pride in its capacity to develop the student's ability to manipulate the material world through its programs in science, medicine, technology, and commerce, it has paid relatively little attention to the student's “inner” development—the sphere of values and beliefs, emotional maturity, moral development, spirituality, and self‐understanding.” —from the Foreword to Encouraging Authenticity and Spirituality in Higher Education by Alexander W. Astin and Helen S. Astin  相似文献   

17.
Spirit Guides     
“Although American higher education can justifiably take pride in its capacity to develop the student's ability to manipulate the material world through its programs in science, medicine, technology, and commerce, it has paid relatively little attention to the student's “inner” development—the sphere of values and beliefs, emotional maturity, moral development, spirituality, and self‐understanding.” —from the Foreword to Encouraging Authenticity and Spirituality in Higher Education by Alexander W. Astin and Helen S. Astin  相似文献   

18.
“Although American higher education can justifiably take pride in its capacity to develop the student's ability to manipulate the material world through its programs in science, medicine, technology, and commerce, it has paid relatively little attention to the student's “inner” development—the sphere of values and beliefs, emotional maturity, moral development, spirituality, and self‐understanding.” —from the Foreword to Encouraging Authenticity and Spirituality in Higher Education by Alexander W. Astin and Helen S. Astin  相似文献   

19.
“Although American higher education can justifiably take pride in its capacity to develop the student's ability to manipulate the material world through its programs in science, medicine, technology, and commerce, it has paid relatively little attention to the student's “inner” development—the sphere of values and beliefs, emotional maturity, moral development, spirituality, and self‐understanding.” —from the Foreword to Encouraging Authenticity and Spirituality in Higher Education by Alexander W. Astin and Helen S. Astin  相似文献   

20.
《Technovation》1999,19(6-7):413-421
The emergence of formal Foresight programmes in science policy across Europe is examined in terms of government's response to the changes in, and especially the uncertainties of, contemporary innovation. The paper explores this through deploying Beck's notion of the “risk society”, asking how far Foresight can be construed as the management of new technologies by the transition towards the “negotiation state”. It shows how, through a discussion of the social management of new health technologies, a tension arises between the priorities and regimes of the new “negotiation” and those of the former “provident” (or welfare) state. The emergence of new technologies will be shaped by the institutional assumptions and processes operating within the different policy regimes.  相似文献   

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