Experts frequently adjust statistical model-based forecasts. Sometimes this leads to higher forecast accuracy, but expert forecasts can also be dramatically worse. We explore the potential drivers of the relevance and quality of experts' added knowledge. For that purpose, we examine a very large...

Economic variables like GDP growth, employment, interest rates and consumption show signs of cyclical behavior. Many variables display multiple cycles, with lengths ranging in between 5 to even up to 100 years. We argue that multiple cycles can be associated with long-run stability of the...

In this paper it is advocated to select a model only if it significantly contributes to the accuracy of a combined forecast. Using hold-out-data forecasts of individual models and of the combined forecast, a useful test for equal forecast accuracy can be designed. An illustration for real-time...

A strong link exists between Randstad's temporary sta±ng services and Dutch GDP. The two annual series share a stochastic trend and two long-swing deterministic cycles. Causality appears to run from temporary sta±ng to GDP and not vice versa. These features are taken aboard in a simple...

We perform a large-scale empirical analysis of the question whether model-based forecasts can be improved by adding expert knowledge. We consider a huge database of a pharmaceutical company where the head office uses a statistical model to generate monthly sales forecasts at various horizons for...

It frequently occurs that experts adjust forecasts from statistical models. There is some evidence that such adjusted forecasts can lead to substantially better performance. Little is known about competence and confidence effects in what these experts do. Theoretical and experimental results in...

Theory predicts that dismissing the 1 and 2 euro cent coins from the denominational range of the euro leads to more payment efficiency. To examine whether this theory holds true in practice, we collected data for the Netherlands before and after September 1 2004, which marks the day that retail...

This report presents a comprehensive review of the maritime safety regimes and provides recommendations on how to improve the system. The results show a complex legal framework which generates a high amount of inspections and overlapping of inspection areas where no cross-recognition is...

Consumer preferences can be measured by rankings of alternatives. When there are too many alternatives, this consumer task becomes complex. One option is to have consumers rank only a subset of the available alternatives. This has an impact on subsequent statistical analysis, as now a large...

In business and in macroeconomics it is common practice to use econo- metric models to generate forecasts. These models can take any degree of sophistication. Sometimes it is felt by an expert that the model-based fore- cast needs adjustment. This paper makes a plea for a formal approach to such...