Unit Root CADF Testing with R

This paper describes CADFtest, an R package for testing for the presence of a unit root in a time series using the covariate-augmented Dickey-Fuller (CADF) test proposed in Hansen (1995). The procedures presented here are user friendly, allow fully automatic model specification, and allow computation of the asymptotic p values of the test.

INCREASING AT AN INCREASING RATE: THE POTENTIAL CONVEXITY OF DISCRETE-CHOICE WELFARE MEASURES

When environmental quality enters random utility models linearly, welfare measures are convex in quality. The convexity is partly due to site substitution, and it has policy implications for whether changes in quality should be concentrated or diffuse. These functional form effects are illustrated in a model of Great Lakes fishing.Environmental Economics and Policy,

Covariate Augmented Dickey-Fuller Tests with R

This paper describes CADFtest, a R (R Development Core Team 2008) package for testing for the presence of a unit root in a time series using the Covariate Augmented Dickey-Fuller (CADF) test proposed in Hansen (1995). The procedures presented here are user friendly, allow fully automatic model specification, and allow computation of the asymptotic p-values of the test.unit root, stationary covariates, asymptotic p-values, R.

Are credit constraints in Italy really more binding in the South?

This paper is motivated by a very practical question: are there significant geographical differences in the accessibility to the credit market on the part of Italian households? The investigation is carried using robust probit model. Estimation is carried out in a Bayesian framework. The results are somewhat surprising, showing that the area where households are more likely to be credit constrained is not the South, as could be easily imagined, but rather the highly developed and industrialized North-West.

A simple panel-CADF test for unit roots

Copyright © Blackwell Publishing Ltd and the Department of Economics, University of Oxford 2012. This is the accepted version of the following article: Costantini, M. and Lupi, C. (2013), A Simple Panel-CADF Test for Unit Roots. Oxford Bulletin of Economics and Statistics, 75: 276–296, which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1111/j.1468-0084.2012.00690.x/abstract.In this paper, we propose a simple extension to the panel case of the covariate-augmented Dickey–Fuller (CADF) test for unit roots developed in Hansen (1995). The panel test we propose is based on a P values combination approach that takes into account cross-section dependence. We show that the test has good size properties and gives power gains with respect to other popular panel approaches. An empirical application is carried out for illustration purposes on international data to test the purchasing power parity (PPP) hypothesis

Reverse engineering applied to a lumbar vertebra

Bone studies can be made in vivo or in vitro. However, disadvantages of both traditional techniques call for a compromise between the two. Reverse engineering allows in vitro bone samples to be simulated and analysed in a virtual in vivo environment thus offering a middle ground solution and a sound foundation on which biomechanical studies of bone could develop.peer-reviewe

Platform Competition and Broadband Uptake: Theory and Empirical Evidence from the European Union

Broadband access provides users with high speed, always-on connectivity to the Internet. Due to its superiority, broadband is seen as the way for consumers and firms to exploit the great potentials of new applications. This has generated a policy debate on how to stimulate adoption of broadband technology. One of the most disputed issues is about competition policies: these may be intended to promote competition in the Digital Subscriber Line (DSL) segment of the market (intra- platform competition), or to stimulate entry into the market for alternative platforms such as cable access or fiber optics (inter- platform competition). Using a model of oligopoly competition between differentiated products, our paper explicitly studies the effect of inter and intra platform competition on the diffusion of broadband access. The implications of the model are then tested using data from 14 European countries. The econometric evidence confirms the results of the theoretical model and indicates that while inter-platform competition drives broadband adoption, competition in the market for DSL services does not play a significant role. The results also confirm that lower unbundling prices stimulate broadband uptake.Broadband, inter-platform and intra-platform competition,local loop unbundling

A Simple Panel-CADF Test for Unit Roots

In this paper we propose a simple extension to the panel case of the covariate-augmented Dickey Fuller (CADF) test for unit roots developed in Hansen (1995). The extension we propose is based on a p-values combination approach that takes into account cross-section dependence. We show that the test is easy to compute, has good size properties and gives power gains with respect to other popular panel approaches. A procedure to compute the asymptotic p-values of Hansen’s CADF test is also a side-contribution of the paper. We also complement Hansen (1995) and Caporale and Pittis (1999) with some new theoretical results. Two empirical applications are carried out for illustration purposes on international data to test the PPP hypothesis and the presence of a unit root in international industrial production indices.Unit root, panel data, approximate p-values, Monte Carlo

Stochastic convergence among European economies

The aim of this paper is to test the stochastic convergence in real per capita GDP for 15 European countries using non-stationary panel data approaches over the period 1950-2003. Cross-sectional dependence is assumed due to the existence of strong linkages among European economies. However, tests derived under the assumption of cross-sectional independence are also carried out for completeness and comparison. We also split the whole sample into two sub-periods (1950-1976, 1977-2003) in order to take into account the effects of the first oil crisis (1973-1974) and to evaluate the robustness of the statistical analysis. Our results offer little support to the stochastic convergence hypothesis for the whole period, while suggest the presence of convergence in the first sub-period.Convergence