This paper presents a family of simple nonparametric unit root tests indexed by one parameter, d, and containing Breitung’s (2002) test as the special case d = 1. It is shown that (i) each member of the family with d 0 is consistent, (ii) the asymptotic distribution depends on d, and thus...

We present evidence on one facet of energy security in OECD economies - the extent of diversification in sources of oil and natural gas supplies. Viewed from the perspective of the energy-importing countries as a whole, there has not been much change in diversification in oil supplies over the...

For both deterministic or stochastic regressors, as well as parametric nonlinear or linear regression functions, we prove the weak consistency of the coefficient estimators for the Type I censored quantile regression model under different censoring mechanisms with censoring points depending on...

This paper formulated a short-run model, with an explicit role for monetary policy, for analyzing world oil and gas markets. The model described carefully the parameters of these markets and their vulnerability to business cycles. Estimates showed that short-run demand for oil and gas was price-...

This paper attempts to offer specific inputs to the debate on local content promotion in the oil industry, using the specific case of São Tomé and Príncipe as point of reference. Our approach emphasizes inter-sectoral linkages and institutional pre-conditions for local content promotion....

This paper tests the hypothesis that real per capita income growth rates are random walks against the hypothesis implied by models of endogenous growth that they are stationary. Thereby the influence of the choice of different test statistics as well as the choice of the H0 on the test results...