James Hamilton, 22 June 2017

In economic research, the Hodrick-Prescott filter is a widely used tool for removing cyclical components from time-series data. This column argues that, despite its popularity, the HP filter has serious drawbacks that should severely restrict its application. It involves several levels of differencing, so that for random walk series, subsequently observed patterns are likely to be artefacts of having applied the filter, rather than due to the underlying data-generating process. The column goes on to suggest an alternative to the HP filter that avoids these pitfalls. 

Lucrezia Reichlin, 28 September 2016

How can we build models that handle uncertainty? In this video Lucrezia Reichlin discusses her work on building models that handle multiple time series simultaneously. This video was recorded during the European Economic Association's Congress held in Geneva at the end of August 2016. 

Longfeng Ye, Peter Robertson, 01 February 2016

The World Bank has identified 37 countries as being in a ‘middle-income trap’, but few formal tests of the middle-income trap hypothesis exist. This column presents a new test based on a more nuanced observation that incorporates information on a country’s long-run growth path. Only seven out of 46 middle-income countries are found to be potentially ‘trapped’. Some countries that are usually considered to be trapped may just be growing very slowly.

Patrick Minford, 04 January 2015

Out-of-sample forecasting tests are increasingly used to establish the quality of macroeconomic models. This column discusses recent research that assesses what these tests can establish with confidence about macroeconomic models’ specification and forecasting ability. Using a Monte Carlo experiment on a widely used macroeconomic model, the authors find that out-of-sample forecasting tests have weak power against misspecification and forecasting performance. However, an in-sample indirect inference test can be used to establish reliably both the model’s specification quality and its forecasting capacity.


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