Further Evidence on the Great Crash, the Oil Price Shock, and the Unit Root Hypothesis

Recently Perron (1989) has carried out tests of the unit root hypothesis against the alternative hypothesis of trend stationarity with a break in the trend occurring at the Great Crash of 1929 or at the 1973 oil price shock. His analysis covers the Nelson-Plosser macroeconomic data series as well as a post-war quarter real GNP series. His tests reject the unit root null hypothesis for most of the series. This paper takes issue with the assumption used by Perron that the Great Crash and the oil price shock can be treated as exogenous events. A variation of Perron’s test is considered in which the break point is estimated rather than fixed. We argue this test is more appropriate than Perron’s, since it circumvents the problem of data-mining. The asymptotic distribution of the “estimated break point” test statistic is determined. The data series considered by Perron are reanalyzed using this test statistic. The empirical results make use of the asymptotics developed for the test statistic as well as extensive finite sample corrections obtained by simulation. The effect on the empirical results of fat-tailed and temporally dependent innovations is investigated. In brief, by treating the break point as endogenous, we find that there is less evidence against the unit root hypothesis than Perron finds for many of the data series, but stronger evidence against it for several of the series, including the Nelson-Plosser industrial production, nominal GNP, and real GNP series

Unit root testing under a local break in trend using partial information on the break date*

We consider unit root testing allowing for a break in trend when partial information is available regarding the location of the break date. This takes the form of knowledge of a relatively narrow window of data within which the break takes place, should it occur at all. For such circumstances, we suggest employing a union of rejections strategy, which combines a unit root test that allows for a trend break somewhere within the window, with a unit root test that makes no allowance for a trend break. Asymptotic and _nite sample evidence shows that our suggested strategy works well, provided that, when a break does occur, the partial information is correct. An empirical application to UK interest rate data containing the 1973 ‘oil shock’ is also considered

Tests of the co-integration rank in VAR models in the presence of a possible break in trend at an unknown point

In this paper we consider the problem of testing for the co-integration rank of a vector autoregressive process in the case where a trend break may potentially be present in the data. It is known that un-modelled trend breaks can result in tests which are incorrectly sized under the null hypothesis and inconsistent under the alternative hypothesis. Extant procedures in this literature have attempted to solve this inference problem but require the practitioner to either assume that the trend break date is known or to assume that any trend break cannot occur under the co-integration rank null hypothesis being tested. These procedures also assume the autoregressive lag length is known to the practitioner. All of these assumptions would seem unreasonable in practice. Moreover in each of these strands of the literature there is also a presumption in calculating the tests that a trend break is known to have happened. This can lead to a substantial loss in finite sample power in the case where a trend break does not in fact occur. Using information criteria based methods to select both the autoregressive lag order and to choose between the trend break and no trend break models, using a consistent estimate of the break fraction in the context of the former, we develop a number of procedures which deliver asymptotically correctly sized and consistent tests of the co-integration rank regardless of whether a trend break is present in the data or not. By selecting the no break model when no trend break is present, these procedures also avoid the potentially large power losses associated with the extant procedures in such cases

Will the US Economy Recover in 2010? A Minimal Spanning Tree Study

We calculated the cross correlations between the half-hourly times series of the ten Dow Jones US economic sectors over the period February 2000 to August 2008, the two-year intervals 2002--2003, 2004--2005, 2008--2009, and also over 11 segments within the present financial crisis, to construct minimal spanning trees (MSTs) of the US economy at the sector level. In all MSTs, a core-fringe structure is found, with consumer goods, consumer services, and the industrials consistently making up the core, and basic materials, oil and gas, healthcare, telecommunications, and utilities residing predominantly on the fringe. More importantly, we find that the MSTs can be classified into two distinct, statistically robust, topologies: (i) star-like, with the industrials at the center, associated with low-volatility economic growth; and (ii) chain-like, associated with high-volatility economic crisis. Finally, we present statistical evidence, based on the emergence of a star-like MST in Sep 2009, and the MST staying robustly star-like throughout the Greek Debt Crisis, that the US economy is on track to a recovery.Comment: elsarticle class, includes amsmath.sty, graphicx.sty and url.sty. 68 pages, 16 figures, 8 tables. Abridged version of the manuscript presented at the Econophysics Colloquim 2010, incorporating reviewer comment

Consumption of salt rich products: impact of the UK reduced salt campaign

This paper uses a leading UK supermarket’s loyalty card database to assess the effectiveness and impact of the 2004 UK reduced salt campaign. We present an econometric analysis of purchase data to assess the effectiveness of the Food Standard Agency’s (FSA) ‘reduced salt campaign’. We adopt a general approach to determining structural breaks in the time series of purchase data, using unit root tests whereby structural breaks are endogenously determined from the data. We find only limited evidence supporting the effectiveness of the FSA’s reduced salt campaign. Our results support existing findings in the literature that have used alternative methodologies to examine the impact of information campaigns on consumer choice of products with high salt content

Structural change and foreign direct investment : globalization and regional economic integration

This paper investigates flows of inward and outward foreign direct investment (FDI) and FDI-to-GDP ratios in a sample of 62 countries over a 30 year time span. Using several endogenous structural break procedures (allowing for one and two break points), we find that: (1) the great majority of the series have structural breaks in the last 15 years, (2) post-break FDI and FDI/GDP ratios are substantially higher than the pre-break values, and (3) most breaks seem to be related to globalization, regional economic integration, economic growth, or political instability. Static and dynamic panel-data analy- ses accounting for and/or addressing endogeneity, simultaneity, nonstationar- ity, heterogeneity and cross-sectional dependence show that FDI is negatively related to exchange rate volatility and GDP per capita, but positively related to some regional integration agreements, trade openness, GDP, and GDP growth. Most notably, the European Union is the only regional economic integration unit found to consistently have significant and positive effects on FDI.info:eu-repo/semantics/publishedVersio