A new multi-logistic methodology to analyze long range time series of evolutionary S-shaped processes is presented. It conceptually innovates over the traditional logistic approach. The ansatz includes computing the residuals to an optimized multi-logistic trend curve least squares fitted to the time-series data. The elements of the residuals series are checked for autocorrelations and once detected the residuals series is further analyzed to search for eventual presence of underlying periodic structures using a truncated Fourier sine series. The method foundations ensures both a universal applicability and a capacity to disclose the existence of active clocks that can be possibly traced to the driving motors of the evolutionary character of the time series, due to the responsiveness of corresponding process to the development of economic cycles. On associating these two views, it is found that the methodology has a strong potential to improve the quality of short-term forecasts. These findings have been put to test through applications of the methodology to studying the time evolution of two commodities of strong economic and social importance (corn and steel) and good results were consistently obtained for both the analytical and forecasting aspects. 相似文献
With a combined career of over 60 years in oncology nursing, the authors reflect on the critical elements in the question, "How can we afford to die?" Three high-profile patient scenarios in three different decades promised to improve use of advance directives but did not. Recent societal events, including the debates about health care reform, have brought attention again to end-of-life issues and care. Quickly approaching a "perfect storm" of an aging population, an inefficient and costly illness-oriented health care system, and health care profession shortages, the United States will not be able to afford delivering futile interventions. Nurses, who are consistently seen as the most trusted professionals, must take action in strategies the authors present. 相似文献
In this article we use an autoregressive fractionally integrated moving average approach to measure the degree of fractional integration of aggregate world CO2 emissions and its five components – coal, oil, gas, cement, and gas flaring. We find that all variables are stationary and mean reverting, but exhibit long-term memory. Our results suggest that both coal and oil combustion emissions have the weakest degree of long-range dependence, while emissions from gas and gas flaring have the strongest. With evidence of long memory, we conclude that transitory policy shocks are likely to have long-lasting effects, but not permanent effects. Accordingly, permanent effects on CO2 emissions require a more permanent policy stance. In this context, if one were to rely only on testing for stationarity and non-stationarity, one would likely conclude in favour of non-stationarity, and therefore that even transitory policy shocks have permanent effects. Our fractional-integration analysis highlights that this is not the case. 相似文献
This paper examines the effect of network properties on the performance R&D joint projects. In particular, we examine the impact of network cohesion, diversity and shape on the performance of these of exploration and exploitation R&D projects. We test these measures using data on projects from European R&D networks developed under the framework of Eureka projects. The empirical results indicated some network properties enhance the project’s performance and these differ depending on the kind of technological project developed. Our results suggest a lower heterogeneity, greater cohesion and network centralisation in exploitation than in exploration projects. Our findings show different types of structures depending on the aim of the joint project and that there exist different degrees of cohesion between the partners that comprise the core and the peripheral nodes. 相似文献
Conclusion After a relatively long period of discussion, characterised by an uncertain approach towards transition, the Soviet authorities are now moving with decision towards the market. This statement applies to the reform as a whole and in particular to convertibility.The convertibility process in the Soviet Union started from a relatively unfavourable position: not only because of the complete (internal and external) inconvertibility of the Rouble, but also because the country's past displays a sort of structural propensity towards inconvertibility.It took the Soviet authorities some years to dismiss the doctrine of a parallel currency and the idea that convertibility is the final step of the transition. Recent legislative production in the Soviet Union (in particular the Banking law and the Currency law) are a good sign that they are proceeding in the right direction and practical experience seems to confirm this statement.In 1991 the process has accelerated and more important progress was made towards unification of the exchange rates and the creation of a currency market: these are two steps which are fundamental for achieving partial external convertibility (current account operations made by non-residents), which in its turn is the first step towards broader convertibility. Probably within the end of the year external partial convertibility will be reached. This at last will increase the foreign contribution to the Soviet economy, thus improving domestic conditions. The events of August 1991 will most likely further accelerate the pace of the process, which is now without doubt irreversible.Even if qualitatively positive results are achieved in the reform process however, great effort must still be made not only to complete and consolidate these results, but also to proceed further towards internal and financial convertibility. 相似文献
This paper examines the spillover effects and the causality between inflation, output growth and its uncertainties for India. Using monthly data for the period from April 1980 to April 2011, we estimated a bi-variate GARCH in mean with BEKK representations. This study differs from the earlier works where the parameters in the BEKK representations are estimated individually and the inferences are drawn on the basis of the individual lagged variance, covariance, and error terms from the respective equations. The empirical evidence suggests that inflation uncertainty seems to have significant negative impact on output growth and positive impact on output uncertainty and there is a positive influence of output uncertainty on the inflation. More importantly, there are spillovers and volatility transmission effects between the macroeconomic uncertainties where the volatility in output growth is significantly influenced by the shocks and volatility in inflation.
This article discusses Bayesian inference in change‐point models. The main existing approaches treat all change‐points equally, a priori, using either a Uniform prior or an informative hierarchical prior. Both approaches assume a known number of change‐points. Some undesirable properties of these approaches are discussed. We develop a new Uniform prior that allows some of the change‐points to occur out of sample. This prior has desirable properties, can be interpreted as “noninformative,” and treats the number of change‐points as unknown. Artificial and real data exercises show how these different priors can have a substantial impact on estimation and prediction. 相似文献
In recent years scholars have begun to focus on the consequences of individuals' exposure to civil war, including its severe health and psychological consequences. Our innovation is to move beyond the survey methodology that is widespread in this literature to analyze the actual behavior of individuals with varying degrees of exposure to civil war in a common institutional setting. We exploit the presence of thousands of international soccer (football) players with different exposures to civil conflict in the European professional leagues, and find a strong relationship between the extent of civil conflict in a player's home country and his propensity to behave violently on the soccer field, as measured by yellow and red cards. This link is robust to region fixed effects, country characteristics (e.g. rule of law, per capita income), player characteristics (e.g. age, field position, quality), outliers, and team fixed effects. Reinforcing our claim that we isolate the effect of civil war exposure rather than simple rule breaking or something else entirely, there is no meaningful correlation between our measure of exposure to civil war and soccer performance measures not closely related to violent conduct. The result is also robust to controlling for civil wars before a player's birth, suggesting that it is not driven by factors from the distant historical past. 相似文献