I can't review this, but perhaps someone on this list can. please respond to paul. thanks. -rich >Date: Mon, 13 Nov 2000 19:50:17 -0800 >From: "Paul H. Rosenberg" <[log in to unmask]> >To: Rich Cowan <[log in to unmask]> >Subject: Statistical Explanation > >Rich, > >Let me know if this fills the bill as an explanation. > > -- Paul > >=========================================== >No Buchanan Stronghold In Palm Beach County: A Statistical Analysis >Explained > >One of the myriad false claims made by the Bush campaign is that Palm >Beach County is a Bushanan stronghold, and one of the few reasons given >for this claim is the fact that John McGuire, a Reform Party candidate >for Congress made a strong showing. McGuire got 2,651in just a third of >the county, for 2.1% of the vote--a much better showing than Buchanan, >who got 0.79%. It would seem more sensible to call this John McGuire >stronghold. > >And what kind of politician is John McGuire? Well, for one thing he >probably wouldn't like me calling him a politician. I interviewed him >on Sunday, November 12. He identified himself with the pre-Buchanan >Reform Party, and while he wouldn't say anything negative about >Buchanan, he made it quite clear that he wasn't running on the same >issues as Buchanan. > >But still, the question remains: Does McGuire's relatively strong >showing provide evidence that Buchanan's relatively strong showing is >real? The only way to definitively prove this would be to compare every >single ballot, and see if the same people voted for both of them. We >don't have the data to do that. But we do have the data to compare >voting strength at the precinct level. And here we find that McGuire >did best where Nader was strongest. > >The statistical tool for making this analysis is called a correlation >coefficient, which ranges from 1.0 (for a perfect correspondence) to 0.0 >(for no correspondence) to -1.0 (for a perfect negative >correspondence).* The table below shows that apparent Buchanan >strongholds were no better for McGuire than Gore strongholds--in fact >they were just a tiny bit worse. > >Precinct-level Correlations Between Reform Party Candidate for Congress >John McGuire and all presidential candidates. > >Nader 0.643 >Browne 0.166 >Bush 0.162 >Gore 0.136 >Buchanan 0.134 >Phillips 0.084 >Hagelin 0.063 >Moorehead 0.035 >Harris -0.014 >McReynold -0.063 > >These figures were generated by a fairly simple process: > >(1) Precinct-level data for all Presidential and Congressional >candidates were converted to percentages. This was necessary to get rid >of the spurious correlation caused by all candidates tending to get more >votes in larger precincts. This data came from two separate sources, >the presidential data covered the whole county, the congressional data >covered slightly less than 30% of it. > >(2) McGuire's data was merged together with the presidential data on a >single spreadsheet, with all precincts aligned. > >(3) The Excel Correl() function was used to generate correlation >coefficients between McGuire's percentages and those of other >candidates. > >Excel Help explains the Correl function as follows: > >Correl > >Returns the correlation coefficient of the array1 and array2 cell >ranges. Use the correlation coefficient to determine the relationship >between two properties. For example, you can examine the relationship >between a location's average temperature and the use of air >conditioners. > >Syntax > >CORREL(array1, array2) > >Array1 is a cell range of values > >Array2 is a second cell range of values > >* An internet reference site, The Statistics Glossary >(http://www.cas.lancs.ac.uk/glossary_v1.1/main.html), explains >correlation coefficients as follows: > >Correlation Coefficient > >A correlation coefficient is a number between -1 and 1 which measures >the degree to which two variables are linearly related. If there is >perfect linear relationship with positive slope between the two >variables, we have a correlation coefficient of 1; if there is positive >correlation, whenever one variable has a high (low) value, so does the >other. If there is a perfect linear relationship with negative slope >between the two variables, we have a correlation coefficient of -1; if >there is negative correlation, whenever one variable has a high (low) >value, the other has a low (high) value. A correlation coefficient of 0 >means that there is no linear relationship between the variables. > > >-- >Paul Rosenberg >Reason and Democracy >[log in to unmask] > >"Let's put the information BACK into the information age!" Organizers' Collaborative PO Box 400897, Cambridge MA 02140 [log in to unmask] www.organizenow.net