摘要:

AbstractPolitical forecasting provides thecontextualityneeded for decision‐making and for forecasting ‘non‐political’ trends. To gear political forecasting to these needs, rather than mimicking approaches in other areas, requires recognition of the distinctive nature of political trends, and realism regarding forecast uses, which generally do not benefit from ‘precise’ probabilities, predictions of only major events, or ‘sophisticated’ methodology that sacrifices comprehensiveness for explicitness. Approaches borrowed from other forecasting disciplines have been counterproductive, although contextual approaches, including cross‐impact analyses and developmental constructs that integrate political and non‐political trends, are promising. Explorations of the consistency of scenario dynamics, taking into account policy responses and non‐formalizable complexity, are also useful. Thus the separation of political forecasting from political analysis should be minimized, calling for a redirection of effort away from developing methodology uniquely geared to forecasting, and towards organizing more comprehensive and systemat

ISSN:0277-6693    

DOI:10.1002/for.3980010303

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY

摘要:

AbstractThe method of ordinary least squares (OLS) and generalizations of it have been the mainstay of most forecasting methodologies for many years. It is well‐known, however, that outliers or unusual values can have a large influence on least‐squares estimators. Users of automatic forecasting packages, in particular, need to be aware of the influence that outlying data values can have on statistical analyses and forecasting results. Robust methods are available to modify least‐squares procedures so that outliers have much less influence on the final estimates; yet these formal methods have not found their way into general forecasting procedures. This paper provides a case study in which classical least‐square‐estimation procedures are complemented with a robust alternative to enhance statistical fit criteria and improve forecasting performance. The study suggests that much can be gained in understanding the nature of outliers and their influence on forecasting performance by performing a robust regression in additi

ISSN:0277-6693    

DOI:10.1002/for.3980010304

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY

摘要:

AbstractThe reported experiment took place in a professional forecasting organization accustomed to giving verbal probability assessments (‘likely’, ‘probable’, etc.). It attempts to highlight the communication problems caused by verbal probability expressions and to offer possible solutions that are compatible with the forecasters overall perspective on their jobsExperts in the organization were first asked to give a numerical translation to 30 different verbal probability expressions most of which were taken from the organization's own published political forecasts. In a second part of the experiment the experts were given 15 paragraphs selected from the organization's political publications each of which contained at least one verbal expression of probability. Subjects were again asked to give a numerical translation to each verbal probability expressionThe results indicate that (a) there is a high variability in the interpretation of verbal probability expressions and (b) the variability is even higher in context. Possible reasons for the context effect are discussed and practical implications are su

ISSN:0277-6693    

DOI:10.1002/for.3980010305

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY

摘要:

AbstractThis paper is concerned with expanding the decision support capabilities of computerized forecasting systems. The expansion allows for the systematic combination of multiple forecasts and the explicit consideration of multiple objectives in the forecast selection process. The methodology used is multiple objective linear programming. Selecting an individual forecast based upon a single objective may not make the best use of available information for a variety of reasons. Combined forecasts may provide a better fit with respect to a single objective than any individual forecast. Even if an individual forecast does provide a good fit with respect to a single objective, a combined forecast may provide a better fit with respect to multiple objectives. An example is used to illustrate the expanded decision support system, its outputs and their properties.

ISSN:0277-6693    

DOI:10.1002/for.3980010306

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY

摘要:

AbstractWhen building regression models for forecasting, analysts often encounter the problem of multicollinearity or illconditioning in their data sets. In such cases, large variances and covariances can make subset selection and parameter estimation difficult to impossible. In this paper, we suggest several approaches for extending estimation results to forecasting and review theoretical results useful for forecasting with multicollinearity. Several examples are provided.

ISSN:0277-6693    

DOI:10.1002/for.3980010307

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY

摘要:

AbstractAlthough‘La Prospective’is not well known in the Anglo‐Saxon forecasting literature, it has been for many years widely used in France and other Latin countries with considerable success. Lately, because of the inaccuracy of forecasting and the large forecasting errors that have been experienced, it is suggested that the Prospective approach can be used as a way of dealing with these problems. The main characteristics of‘La Prospective’are that it does not look at the future as a continuation of the past but rather as the outcome of the wishes of various actors and the constraints imposed on them by the environment. Its purpose is to assist in creating alternative futures and then select some alternative that allows for maximum freedom

ISSN:0277-6693    

DOI:10.1002/for.3980010308

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY

摘要:

AbstractThe settlement delay for very large claims in liability insurance may extend to quite a few years; a delay often years in automobile third‐party liability is by no means an exception. The companies consequently have to set aside huge amounts as provisions for outstanding claims. As the total provision may attain 100 times the underwriting profit, an underestimation of this provision of a few per cent could mean short‐term bankruptcy for the company. A precise forecast of those outstanding liabilities is therefore of crucial importanceOwing to the special nature of the information set (a triangular array of cumulative payments, called the‘run‐off triangle’), actuaries have in the past neglected the time series analysis approach and devised their own forecasting models. Those methods are reviewed, and illustrated by a real‐life example. Two new autoregressive methods a

ISSN:0277-6693    

DOI:10.1002/for.3980010309

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY

ISSN:0277-6693    

DOI:10.1002/for.3980010310

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY

ISSN:0277-6693    

DOI:10.1002/for.3980010311

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY

ISSN:0277-6693    

DOI:10.1002/for.3980010312

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY