C - Mathematical and Quantitative Methods

• Avoiding the Pitfalls: Can Regime-Switching Tests Detect Bubbles?

  Staff Working Paper 1996-11 Simon van Norden, Robert Vigfusson

  Work on testing for bubbles has caused much debate, much of which has focussed on methodology. Monte Carlo simulations reported in Evans (1991) showed that standard tests for unit roots and cointegration frequently reject the presence of bubbles even when such bubbles are present by construction. Evans referred to this problem as the pitfall of testing for bubbles.

  Content Type(s): Staff research, Staff working papers Topic(s): Econometric and statistical methods JEL Code(s): C, C2, C22, C5, C52

• Unit-Root Tests and Excess Returns

  Staff Working Paper 1996-10 Marie-Josée Godbout, Simon van Norden

  Several recent papers have presented evidence from foreign exchange and other markets suggesting that the log of excess returns can be characterized as first-order integrated processes (I(1)). This contrasts sharply with the "conventional" wisdom that log prices are integrated of order one I(1) and that log returns should therefore be integrated of order zero I(0), and even more sharply with the view that past returns have no ability to predict future returns (weak market efficiency).

  Content Type(s): Staff research, Staff working papers Topic(s): Econometric and statistical methods JEL Code(s): C, C1, C12, F, F3, F31

• Does Inflation Uncertainty Vary with the Level of Inflation?

  Staff Working Paper 1996-9 Allan Crawford, Marcel Kasumovich

  The purpose of this study is to test the hypothesis that inflation uncertainty increases at higher levels of inflation. Our analysis is based on the generalized autoregressive conditional heteroscedasticity (GARCH) class of models, which allow the conditional variance of the error term to be time-varying. Since this variance is a proxy for inflation uncertainty, a positive relationship between the conditional variance and inflation would be interpreted as evidence that inflation uncertainty increases with the level of inflation.

  Content Type(s): Staff research, Staff working papers Topic(s): Inflation and prices, Monetary policy and uncertainty JEL Code(s): C, C5, C52, E, E3, E31