Speculative behaviour and oil price predictability

We develop two- and three-state regime switching models and test their forecasting ability for oil prices. We use the deviations of market oil price from fundamental values as the main explanatory variable in our models, while additional potential predictors enrich our specification. Our findings suggest that the regime-switching models are, in general, more accurate than the Random Walk model in terms of both statistical and economic evaluation criteria for oil price forecasts

Club Convergence in Carbon Dioxide Emissions

We examine convergence in carbon dioxide emissions among 128 countries for the period 1960-2003 by means of a new methodology introduced by Phillips and Sul (Econometrica, 2007). Contrary to previous studies, our approach allows us to examine for evidence of club convergence, i.e. identify groups of countries that converge to different equilibria. Our results suggest convergence in per capita CO2 emissions among all the countries under scrutiny in the early years of our sample. However, there seems to be two separate convergence clubs in the recent era that converge to different steady states. Interestingly, we also find evidence of transitioning between the two convergence clubs suggesting either a slow convergence between the two clubs or a tendency for some countries to move from one convergence club to the other.

The Contribution of Growth and Interest Rate Differentials to the Persistence of Real Exchange Rates

This paper employs a new methodology for measuring the contribution of growth and interest rate differentials to the half-life of deviations from Purchasing Power Parity (PPP). Our method is based on directly comparing the impulse response function of a VAR model, where the real exchange rate is Granger caused by these variables with the impulse response function of a univatiate ARMA model for the real exchange rate. We show that the impulse response function of the VAR model is not, in general, the same with the impulse response function obtained from the equivalent ARMA representation, if the real exchange rate is Granger caused by other variables in the system. The difference between the two functions captures the effects of the Granger-causing variables on the half-life of deviations from PPP. Our empirical results for a set of four currencies suggest that real and nominal long term interest rate differentials and real GDP growth differentials account for 22% to 50% of the half-life of deviations from PPP.real exchange rate; persistence measures; VAR; impulse response function; PPP.

Social Discounting Under Uncertainty: A cross-country comparison

Recent research suggests that social cost-benefit analysis should be con- ducted with a declining discount rate. For instance, Newell and Pizer [23] show that the U.S. certainty-equivalent discount rate declines through time, using a simple autoregressive model of U.S. interest rates. This paper extends that line of research, estimating both autoregressive and regime-switching models of real interest rates to determine certainty- equivalent discount rates in Australia, Canada, Germany and the United Kingdom. It is found that the regime-switching model is a better model of past interest rate behavior for all four countries. This model tends to produce a more rapid decline in certainty-equivalent discount rates. The paper provides applications to the economics of climate change and nuclear power.discounting, uncertainty, regime-switching models, climate change policy, nuclear power

Discounting the distant future: How much does model selection affect the certainty equivalent rate?

Evaluating investments with long-term consequences using discount rates that decline with the time horizon, (Declining Discount Rates or DDRs) means that future welfare changes are of greater consequence in present value terms. Recent work in this area has turned towards operationalising the theory and establishing a schedule of DDRs for use in cost benefit analysis. Using US data we make the following points concerning this transition: i) model selection has important implications for operationalising a theory of DDRs that depends upon uncertainty; ii) misspecification testing naturally leads to employing models that account for changes in the interest rate generating mechanism. Lastly, we provide an analysis of the policy implications of DDRs in the context of climate change for the US and show that the use of a state space model can increase valuations by 150% compared to conventional constant discounting.long-run discounting, interest rate forecasting,interest rate forecasting, state-space models,regime-switching models, climate change policy

Declining Discount Rates: Evidence from the UK

We estimate schedules of declining discount rates for cost benefit analysis in the UK. We highlight the importance of model selection for this task and hence for the evaluation of long-term investments, namely climate change prevention and nuclear build.long-run discounting, state-space models,regime-switching models, climate change policy,nuclear build

The Contribution of Growth and Interest Rate Differentials to the Persistence of Real Exchange Rates.

This paper employs a new methodology for measuring the contribution of growth and interest rate differentials to the half-life of deviations from Purchasing Power Parity (PPP). Our method is based on directly comparing the impulse response function of a VAR model, where the real exchange rate is Granger caused by these variables with the impulse response function of a univatiate ARMA model for the real exchange rate. We show that the impulse response function of the VAR model is not, in general, the same with the impulse response function obtained from the equivalent ARMA representation, if the real exchange rate is Granger caused by other variables in the system. The difference between the two functions captures the effects of the Granger-causing variables on the half-life of deviations from PPP. Our empirical results for a set of four currencies suggest that real and nominal long term interest rate differentials and real GDP growth differentials account for 22% to 50% of the half-life of deviations from PPP.real exchange rate; persistence measures; VAR; impulse response function; PPP