Hi, My density estimate for the first difference in probability (question 1.3) looks OK, except it has a really tall spike of values around 0.0. With my background in electronic engineering, I saw this and thought I should try to pass it through some kind of low-pass filter. However, I?m guessing this isn?t the answer. (Removing 0s and 1s from the two vectors of probabilities I took the difference of to get the first difference vector, and running plotting a density plot of this produced something with a smaller 0.0 spike, suggesting a better signal:noise ratio, so conceptually my engineering approach **could** work...) I?m not sure how to ask questions about this without giving away too much detail about what I?ve done (which might be mostly correct) and what my first differences estimate is (which appears reasonable). I am, apparently, the only person doing this course in the UK. So far I seem to have been keeping pace on my own. However, it would be good to have a few people I could work with on the problem set, so I don?t end up emailing this mailing list so often, and/or get stuck on the kinds of little problems which are much easier to see with a fresh pair of eyes. If you think you could offer some advice, let me know. Best wishes, Jon Minton -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.446 / Virus Database: 268.18.13/726 - Release Date: 18/03/2007 15:34 ------------------------------------------------------------------------ _______________________________________________ gov2001-l mailing list gov2001-l at lists.fas.harvard.edu http://lists.fas.harvard.edu/mailman/listinfo/gov2001-l