Online Principal Component Analysis in High Dimension: Which Algorithm to Choose?

Principal component analysis (PCA) is a method of choice for dimension reduction. In the current context of data explosion, online techniques that do not require storing all data in memory are indispensable to perform the PCA of streaming data and/or massive data. Despite the wide availability of recursive algorithms that can efficiently update the PCA when new data are observed, the literature offers little guidance on how to select a suitable algorithm for a given application. This paper reviews the main approaches to online PCA, namely, perturbation techniques, incremental methods and stochastic optimisation, and compares the most widely employed techniques in terms statistical accuracy, computation time and memory requirements using artificial and real data. Extensions of online PCA to missing data and to functional data are detailed. All studied algorithms are available in the  package onlinePCA on CRAN.     

Cyclical Asymmetries in Unemployment Rates: International Evidence

This paper investigates to what extent the observed nonlinearities in the unemployment rates of six major developed economies are the response to cyclical asymmetries. Two classes of models are compared: strict smooth transition autoregressions and models where the transition variable is GDP growth, which is considered a more direct indicator of the business cycle. The empirical evidence points out that nonlinearities in unemployment rates are induced by cyclical asymmetries. It is also found that in most countries the unemployment rate looks stationary and reverts to a long-run equilibrium rate in periods of normal growth, while in extreme cyclical situations it tends to become nonstationary as if each extreme cyclical episode had its own path of equilibrium.      

Is the Euro-Area core price index really more persistent than the food and energy price indexes?

The purpose of this paper is to measure the degree of persistence of the overall, core, food and energy Harmonized Indexes of Consumer Prices for the European Monetary Zone (HICP-EAs) and to identify its implications for decision-making in the private sector and in public policy.Using a non-parametric approach, our results demonstrate the presence of a statistically significant level of persistence in four HICP-EAs: headline, core, food and energy. Moreover, contrary to popular belief, the core index does not reflect permanent price changes. We also find evidence that the food and energy price indexes are more volatile and more persistent than the other two price indexes. Our results also show a reduction in persistence for both the headline and the core price indexes after the implementation of the single monetary policy, but not for food and energy.These results have important implications for both the private sector and for policymakers who use the core price index as a reference in their decision-making. In particular, core price index can lead to erroneous perception of price movements.     

Global Geopolitics and Local Geoeconomics in Northwest Africa: The Industrial Port of Granadilla (Canary Islands,Spain)

In the world scenario of US unilateralism, this paper argues the competition for control over Africa's resources between the major powers (United States, the European Union and China) provides a renewed geostrategic situation for the Canary Islands (Spain). First, the political and economic rivalry over Northwest Africa adds new dimensions to the geostrategic location of the Archipelago, which constitute NATO's southern flank and a logistic platform for neighbouring Africa. Second, it focuses on the particular case of the industrial megaport envisaged for Granadilla (Tenerife), examining its geostrategic projection as an important infrastructure both for the Canarian ruling elites' geoeconomic interests and also for the geopolitical interests of the major world powers.     

Measuring Productive Efficiency in Input–Output Models by Means of Data Envelopment Analysis

The goal of the present research is to evaluate productive efficiency in an input–output framework by means of data envelopment analysis (DEA). This mathematical programming technique allows researchers to assess potential efficiency improvements in the form of input requirements reduction. By constructing envelopment unitary isoquants corresponding to comparable sectors across different local, regional or national economies, e.g. agriculture and manufacturing, DEA identifies as productive benchmarks those economies that exhibit the lowest technical coefficients, i.e. lowest input amount to produce one unit of output. Once these reference frontiers have been defined, it is possible to assess what would be the potential efficiency improvements available to the inefficient economies if they were to produce according to the best practice technologies of their benchmark peers. From an equivalent perspective, these simulations identify the necessary changes that each productive sector needs to undertake in order to reach the efficiency levels of the most successful economies. Finally, within Leontief’s analytical construction, these calculations allow us to assess what would have been the economy‐wid,e benefits for the inefficient economies—in terms of intermediate consumption reductions and final demand increases—of producing with best practice technologies. The model is empirically illustrated using the input–output tables for a set of OECD countries.     

Space-time approach to commercial property prices valuation

There exists three ways of approaching real estate prices: the cost approach, the market data approach and the income capitalization approach. In this article, we propose an improvement of the market data approach that takes into account the spatial component. In particular, we propose a modified market data approach based on interpolation, being the structure of the spatial correlation between the prices of properties the main factor to obtain the weights. Interpolation methods have been widely used for estimating real estate prices, but they do not take into account the structure of their spatial dependence. Although this drawback is overcome by kriged estimation, in the case of the prices of commercial properties, they do not provide good estimates because the scarceness of the market information. This is why auxiliary information is needed and cokriging methods are used to obtain estimates that are more accurate. The aim of this article is the comparison of cokriged estimation of premises prices in two different temporal moments in the emblematic old part of Toledo city (Spain), using housing prices as an auxiliary random function due to their strong correlation with the main one. Cokriging, kriging and inverse distance weighting results are compared.     

How much does water consumption drop when each household takes charge of its own consumption? The case of the city of Seville

Making individuals take charge of their own domestic water consumption is one of the measures used to reduce the growing demand for this resource and to achieve sustainable consumption compatible with the goal of equity. The use of individual meters instead of communal meters and fixing tariffs by inhabitant rather than by household are two measures aimed at achieving these objectives. This article assesses the measures put in place in the Seville metropolitan area during the last 20 years with an unobserved component model set up in a state-space framework estimated using maximum likelihood. Water consumption elasticity to individual meters has changed from –0.307 to –1.317 with the introduction of per inhabitant tariffs, which demonstrates that there are water-saving synergies when the two measures are implemented together. The reductions in water consumption achieved with these measures are also longer lasting than the changes in consumption habits during the frequent droughts in Seville.     

Reported gross income and marginal tax rates: estimation of the behavioural reactions of Spanish taxpayers

This article estimates, for the Spanish personal income tax, the elasticity of reported gross income to marginal tax rates. The identification of this elasticity has been performed using the reform approved by Law 35/2006, which came into force in January 2007. The elasticities obtained suggest the existence of important efficiency costs, with significant regional differences. The average elasticity estimated for Spain as a whole is 0.676. However, this elasticity is highly dispersed throughout the Spanish administrative regions, which indicates the unequal power of distortion of the tax. Thus, households whose principal source of income is salary display an elasticity of 0.337, compared to 0.682 for households whose main income source comes from business or savings. Lastly, a positive correlation is also detected between elasticity and income level: an elasticity of 3.6 is reached for taxpayers with an annual gross income exceeding 100 000€.     

Implications of manager replacement: evidence from the Spanish mutual fund industry

We analyse the financial consequences of manager replacement in a sample that includes all domestic and European equity funds in Spain. Specifically, we examine a total of 104 funds of the sample that experience manager turnover over the period 1999–2009. We find that underperforming funds in the pre-replacement period experience a significant improvement in the excess returns and performance after the manager change, an improvement that lasts over time for domestic equity funds. The analysis of the risk profile indicates that funds experiencing a manager change do not show significantly different levels of risk before the replacement dates although they tend to show an increase in the level of total risk after the change. Finally, the pool-regression analysis of the investment flows confirms that manager changes tend to impact negatively on subsequent flows of those funds with manager turnover.     

Traffic accidents,deaths and alcohol consumption

The main goal of this article is to analyse the relationship existing among prices of alcoholic beverages, alcohol consumption and traffic fatalities for the Spanish Autonomous Communities during the time interval 1998 to 2002. Among the main results, we highlight a positive correlation between alcohol consumption and traffic mortality rate. Basically, governments implement two kinds of policies to reduce the traffic mortality rate. One is oriented to control the supply of alcohol by increasing alcohol taxes. The other is oriented to preserve traffic security, increasing the number of sanctions for traffic rule infraction. We find evidence that both policies exert a positive influence in the reduction of traffic fatalities. There is no empirical evidence to indicate that being a novice driver increases the tendency to be involved in a mortal traffic accident.