The New York State Data Center developed a Statistical Calculations Menu that includes an option for computing the margin of error for the sum of three or more estimates. See attached.

Darlanne Hoctor Mulmat

Applied Research Division – Criminal Justice/Public Policy

San Diego Association of Governments

619-699-7326

From: ctpp-news-bounces@chrispy.net [mailto:ctpp-news-bounces@chrispy.net] On Behalf Of Ed.Christopher@dot.gov
Sent: Tuesday, March 12, 2013 6:57 AM
To: ctpp-news@chrispy.net
Subject: [CTPP] Working with County flow data

Has anyone come up with some easy ways for collapsing and grouping counties together using last week’s county flow data and recalculating new MOEs. I have so many counties that I want to group together that I am looking for a quick way that can handle “lots” of counties.  Another issue I am struggling with is that we are always told not to group more than three variables at a time or the formulas for calculating the new MOE do not really work.  This is particularly troublesome especially if I am trying to group 17 counties together.  What it comes down to is 9 different calculations given that I can only group 3 counties at a time together.  Anyone figure out any short cuts or ways around this short of disregarding the MOEs altogether?  Given all the clustering that I am looking at using the “cheat” sheets I am used to, I will be recalculating MOEs for weeks.  

Ed Christopher