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.

What is behind the recent evolution of Portuguese terms of trade?

This paper analyses the evolution of Portuguese terms of trade over the last decades. Firstly, their evolution is described: (i) terms of trade registered an upward trend since the second half of the 80s, after the apparent stability observed since 1950; (ii) this was a generalized phenomenon across OECD countries; (iii) and it was specially linked to a very contained evolution of import prices. Secondly, terms of trade are broken down by groups of products, and their evolution is decomposed into two components. The first component results from differences in the composition of import and export baskets of goods (inter-sector specialization), while the second emerges from deviations from the law of one price in each sector (intra-sector segmentation). The results show that terms of trade developments were dominated by the specialization effects related to the evolution of oil prices. Excluding energy and focusing in the manufactured goods, the increase in terms of trade is strongly connected with the positive evolution of relative prices inside each sector, in particular in the usually designated traditional sectors: textiles, clothing and footwear. The effects of globalization on import prices and the structural changes in those manufacturing sectors in Portugal are pointed out as explanations for this phenomenon.

The effects of low-cost countries on Portuguese manufacturing import prices

This paper estimates the direct effect of low-cost countries on Portuguese manufacturing import prices, using detailed data both by product and by geographical market for the period 1997-2006. The results point to a negative but modest direct effect when compared with studies available for other countries. This is understandable given the lower share of low-cost countries in Portuguese imports. However, besides this direct effect, import prices were influenced by several other factors, some also related to the increasing presence of low-cost countries in international markets. Overall, this lower direct effect was not reflected in a differentiated evolution of manufacturing import prices in Portugal as its evolution was very close to the average of the euro area countries

Ação anti-tumoral de complexos organometálicos de ouro (I)

Relatório de projeto no âmbito do Programa de Bolsas Universidade de Lisboa/Fundação Amadeu Dias (2011/2012). Universidade de Lisboa. Faculdade de Ciência

Household wealth in Portugal: 1980-2004

The main objective of this paper is to estimate and analyse a relatively long and homogeneous time series (from 1980 onward) on the wealth of households in Portugal. Wealth components covered are financial wealth (financial assets and liabilities) and the housing component of non-financial wealth. We then analyse the results, in terms of developments over the twenty five years under review. For a more recent period, some international comparisons are made, focusing on trends and changes in composition of wealth.