Q1. The primary concern when deciding upon a time series sample period is which of the following factors? A) The length of the sample time period. B) Current underlying economic and market conditions. C) The total number of observations.
Q2. Which of the following statements regarding the instability of time-series models is most accurate? Models estimated with: A) a greater number of independent variables are usually more stable than those with a smaller number. B) shorter time series are usually more stable than those with longer time series. C) longer time series are usually more stable than those with shorter time series.
Q3. The main reason why financial and time series intrinsically exhibit some form of nonstationarity is that: A) most financial and economic relationships are dynamic and the estimated regression coefficients can vary greatly between periods. B) serial correlation, a contributing factor to nonstationarity, is always present to a certain degree in most financial and time series. C) most financial and time series have a natural tendency to revert toward their means.
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发表于 2009-1-10 16:46
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