The Quarterly National Accounts in real-time: an analysis of the revisions over the last decade
In this article, the revisions of the Portuguese Quarterly National Accounts over the last decade are analyzed. We assess the real-time behaviour of GDP estimates and corresponding expenditure and supply side components. In particular, we focus on the revisions up to one year after the release of the fi rst estimate as well as on the revisions resulting from the inclusion of the Annual National Accounts. In the case of GDP, the reliability of the fl ash estimate, more recently made available by INE, is also assessed. The results for GDP suggest that the revisions up to one year are not signifi cant although the revisions can be larger when the Annual National Accounts are included. The expenditure components related with external trade present the largest revisions while the supply side estimates are more fragile than those from the expenditure side.
Back to basics: Data revisions
With few exceptions, most economic data undergo revisions. Although frequently neglected, data revisions may have implications, not only for economic analysis, but also for policy decisions, as revisions may alter current assessment and forecasts of economic developments. In this paper, we reassess data revisions analysis and its impact on forecasting, presenting an encompassing and unified perspective on this subject. For this purpose, we built a real-time database for Portuguese exports and imports of goods. We present a broad set of the measures typically used to gauge revisions and add to this discussion by clarifying the relations between revisions to deferent types of series (for example, revisions to month-on-month and year-on-year rates of change). Furthermore, regarding the (un)predictability of revisions, we suggest an alternative testing approach. The key feature of this approach is that it takes into account both in-sample and out-of-sample performances. We also discuss the impact of revisions on forecasting, focusing on short-term forecasting of first releases. Even though not accounting for data revision implications can lead to suboptimal results, our findings reinforce the need for a case by case analysis.
Targeting oral anticoagulation
Clinical Pharmacology & Therapeutics (2000) 68, 4–5; doi: 10.1067/mcp.2000.108197