In this paper we examine whether WTI and Brent crude oil spot and futures prices (at one, three and six months to maturity) contain a unit root with one and two structural breaks, employing weekly data over the period 1991-2004. To realize this objective we employ Lagrange Multiplier (LM) unit root tests with one and two endogenous structural breaks proposed by Lee and Stazicich (2003, 2004). W...

abstract in this paper we test two versions of convergence hypothesis namely deterministic or conditional convergence and stochastic or catching up hypothesis using carrion-i-silvestre et al. (2005) stationary test. the results show latin and south american countries (lsa) catching up process toward the usa failed in 1980s and somewhat in 1990s. but in 2000s most of them could lie in convergenc...

In many credit risk and pricing applications, credit transition matrix is modeled by a constant transition probability or generator matrix for Markov processes. Based on empirical evidence, we model rating transition processes as piecewise homogeneous Markov chains with unobserved structural breaks. The proposed model provides explicit formulas for the posterior distribution of the time-varying...

his paper tests for evidence in support of the purchasing power parity (PPP) in the bilateral real exchange rate series of the South African rand against the US dollar. The importance of considering structural breaks in the PPP test is illustrated. Using standard unit root tests without considering structural breaks, the study is unable to reject the null hypothesis of a unit root in the exchan...

While a host of economic variables have been identified in the literature with the apparent in-sample ability to predict the equity premium, Goyal and Welch (2007) find that these variables fail to deliver consistent out-of-sample forecast gains relative to the historical average. In this paper, we demonstrate that despite the failure of individual predictive regression model forecasts to outpe...

Although the DNA double-strand break (DSB) is defined as a rupture in the double-stranded DNA molecule that can occur without chemical modification in any of the constituent building blocks, it is recognized that this form is restricted to enzyme-induced DSBs. DSBs generated by physical or chemical agents can include at the break site a spectrum of base alterations (lesions). The nature and num...