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21.
Luiz C.M. Miranda C.A.S. LimaAuthor vitae 《Technological Forecasting and Social Change》2011,78(8):1445-1470
Logistic and power law methodologies for both retrospective and prospective analyses of extended time series describing evolutionary growth processes, in environments with finite resources, are confronted. While power laws may eventually apply only to the early stages of said growth process, the Allee logistic model seems applicable over the entire span of a long range process. On applying the Allee logistic model to both the world population and the world gross domestic product time series, from 1 to 2008 AD, a projection was obtained that along the next few decades the world should experience a new economic boom phase with the world GDP peaking around the year 2020 and proceeding from then on towards a saturation value of about 142 trillion international dollars, while the world population should reach 8.9 billion people by 2050. These results were then used to forecast the behavior of the supply and consumption of energy and food, two of the main commodities that drive the world system. Our findings suggest that unless the currently prevailing focus on economic growth is changed into that of sustainable prosperity, human society may run into a period of serious economical and social struggles with unpredictable political consequences. 相似文献
22.
Macroeconomic forecasting using structural factor analysis 总被引:1,自引:0,他引:1
The use of a small number of underlying factors to summarize the information from a much larger set of information variables is one of the new frontiers in forecasting. In prior work, the estimated factors have not usually had a structural interpretation and the factors have not been chosen on a theoretical basis. In this paper we propose several variants of a general structural factor forecasting model, and use these to forecast certain key macroeconomic variables. We make the choice of factors more structurally meaningful by estimating factors from subsets of information variables, where these variables can be assigned to subsets on the basis of economic theory. We compare the forecasting performance of the structural factor forecasting model with that of a univariate AR model, a standard VAR model, and some non-structural factor forecasting models. The results suggest that our structural factor forecasting model performs significantly better in forecasting real activity variables, especially at short horizons. 相似文献
23.
Forecasting of electricity costs based on an enhanced gray-based learning model: A case study of renewable energy in Taiwan 总被引:1,自引:0,他引:1
Shun-Chung LeeAuthor Vitae Li-Hsing Shih Author Vitae 《Technological Forecasting and Social Change》2011,78(7):1242-1253
This work presents a novel gray-based cost efficiency (GCE) model that integrates the gray forecasting model into a two-factor cost efficiency curve model for renewable energy (RE) technologies and identifies the optimal forecasting model for power generation cost of RE technologies. The analytical framework of proposed GCE model improves short-term prediction of power generation cost, and can be applied during the early developmental stages for RE technologies. Empirical analysis is based on wind power data for Taiwan. Time lag of knowledge stock was simulated to represent the actual relationship between R&D expenditures and cost reductions in power generation by knowledge stock. Analytical results demonstrate the GCE model is a useful tool to quantify the influences of cost reductions in power generation. The implications of analytical results are that institutional policy instruments play an important role in RE technologies achieving cost reductions and market adoption. The proposed GCE model can be applied to all high-technology cases, and particularly to RE technologies. The study concludes by outlining the limitations of the proposed GCE model and directions for further research. 相似文献
24.
Clive-Steven CurranAuthor Vitae Jens LekerAuthor Vitae 《Technological Forecasting and Social Change》2011,78(2):256-273
The blurring of boundaries between hitherto distinct scientific disciplines, technologies or markets is a common and powerful phenomenon. Concentrating on monitoring convergence through patent indicators, we discuss convergence with examples from the area of Nutraceuticals and Functional Foods (NFF)/Cosmeceuticals as well as information technologies, consumer electronics, and telecommunications (ICT). We analyze 7455 scientific and patent references on phytosterols with the aid of SciFinder Scholar and 3836 documents employing STN AnaVist. Furthermore, we test an IPC co-classification based approach on 859,469 ICT-related and 341,846 NFF-related patents. Our results show clear indications for convergence and a proof of principle for our monitoring concept. Academics may better evaluate environmental parameters, like cases of convergence, influencing companies' actions. Implications for practitioners are based on a more reliable assessment prior to the forming of strategic alliances or mergers and acquisitions. This could help avoid costly adventures such as the mergers and acquisitions seen in ICT. 相似文献
25.
Andreas Graefe J. Scott Armstrong Randall J. Jones Jr. Alfred G. Cuzán 《International Journal of Forecasting》2014
We summarize the literature on the effectiveness of combining forecasts by assessing the conditions under which combining is most valuable. Using data on the six US presidential elections from 1992 to 2012, we report the reductions in error obtained by averaging forecasts within and across four election forecasting methods: poll projections, expert judgment, quantitative models, and the Iowa Electronic Markets. Across the six elections, the resulting combined forecasts were more accurate than any individual component method, on average. The gains in accuracy from combining increased with the numbers of forecasts used, especially when these forecasts were based on different methods and different data, and in situations involving high levels of uncertainty. Such combining yielded error reductions of between 16% and 59%, compared to the average errors of the individual forecasts. This improvement is substantially greater than the 12% reduction in error that had been reported previously for combining forecasts. 相似文献
26.
在多角度界定影子银行的基础上,总结中国影子银行的主要特征,即处于初期发展阶段、杠杆率相对较低、主体独立性低、金融创新活跃地带。从欧美国家影子银行发展实践来看,中国影子银行是金融体制过渡性的产物,代表了未来金融创新的方向,其发展趋势主要包括:业务发展:由银行表外业务向资产证券化业务转变;运作模式:由"一对一"对接向"多对多"对接转变;融资结构:由非标债权融资向标准化债权融资转变;体系构成:由商业银行为主向非银行金融机构为主转变;监管动向:由机构监管向机构监管与功能监管相结合转变。 相似文献
27.
Since the early days of option pricing theory,the assumption that the dividends on the underlying stock or index over the
life of the contract are known has not been challenged. We examine the sensitivity of index option prices to the assumption
of dividend uncertainty. We consider a number of issues related to the forecasting of dividends and build a dividend forecasting
model that passes several rigorous tests for unbiasedness. We then generate option prices using contemporary market levels
and interest rates. We find that prices generated with the actual dividends are unbiased with respect to those generated using
the forecasted dividends. The magnitudes of the forecast errors, however, are sufficiently large to suggest a concern, but
the percentage errors are consistently small, typically amounting to less than two percent of the option price. We conclude
that the convenient assumption that the stream of future dividendsis known is probably innocuous.
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
28.
Frank van Berkum Katrien Antonio Michel Vellekoop 《Scandinavian actuarial journal》2016,2016(7):581-603
Most mortality models proposed in recent literature rely on the standard ARIMA framework (in particular: a random walk with drift) to project mortality rates. As a result the projections are highly sensitive to the calibration period. We therefore analyse the impact of allowing for multiple structural changes on a large collection of mortality models. We find that this may lead to more robust projections for the period effect but that there is only a limited effect on the ranking of the models based on backtesting criteria, since there is often not yet sufficient statistical evidence for structural changes. However, there are cases for which we do find improvements in estimates and we therefore conclude that one should not exclude on beforehand that structural changes may have occurred. 相似文献
29.
Philippe Mongrain Richard Nadeau Bruno Jérôme 《International Journal of Forecasting》2021,37(1):289-301
Election forecasting has become a fixture of election campaigns in a number of democracies. Structural modeling, the major approach to forecasting election results, relies on ‘fundamental’ economic and political variables to predict the incumbent’s vote share usually a few months in advance. Some political scientists contend that adding vote intention polls to these models—i.e., synthesizing ‘fundamental’ variables and polling information—can lead to important accuracy gains. In this paper, we look at the efficiency of different model specifications in predicting the Canadian federal elections from 1953 to 2015. We find that vote intention polls only allow modest accuracy gains late in the campaign. With this backdrop in mind, we then use different model specifications to make ex ante forecasts of the 2019 federal election. Our findings have a number of important implications for the forecasting discipline in Canada as they address the benefits of combining polls and ‘fundamental’ variables to predict election results; the efficiency of varying lag structures; and the issue of translating votes into seats. 相似文献
30.