Should our function in 1B take a value for sigma as well, since we are trying to optimize our log likelihood function of beta *and* sigma? If no, how does one get the value of sigma that you need to calculate the log likelihood? Just concerned because it mentions our log likelihood taking a beta, but not a sigma. (Also, if it is yet another parameter to throw into the function, how does one optim over two variables?) ~Meryl _______________________________________________ gov2001-l mailing list gov2001-l at lists.fas.harvard.edu http://lists.fas.harvard.edu/mailman/listinfo/gov2001-l