This seems like an aggregate v record level ratio.   I might solve this by grouping in a summary statistic in a PROC SQL using a group by statement   like so   PROC SQL; create table want as select *, sum(y1) as totalY1, sum(y2) as totalY2, sum(y1)/sum(y2) as RatioY1_Y2 from havedatasample group by city, store; quit; run;   ... View more

This may work fine or give you the general idea of how it would work. %marco sensitivityfactoring( varname, UporDown, libin, datasetin, libout, datasetout); /*comment explaining the macro program parameters above*/ /*marco (variable name, the words UP or DOWN, path to library/folder where your data are, datasetin is the name of the dataset, path to library/folder where your new data will go, datasetin is the name of the new dataset,*/ /*Macro program*/ /* define libname*/ libname datain "&libin."; /* path to library/folder where your data are.*/ /*bring data into work directory*/ data haveoriginal; set datain..&datasetin.; /* the & and period(s) (.) here are important*/ /* datasetin is the name of the dataset */ run; %if "&UporDown."="UP" %then %let Sensitivityfactor=1.1; /* we are moving the variable data up 10%*/ %else %if "&UporDown."="DOWN" %then %let Sensitivityfactor=0.9; /* we are moving the variable data down 10%*/ /* define libname*/ libname dataout "&libout."; /* path to library/folder where your data are.*/ data daatout.&datasetout.; set haveoriginal; /* we know what variable we want to change because it's name is in this macro parameter variable name "varname"*/ &varname.=&varname.*&Sensitivityfactor.; run; /* we are done now.*/ %mend; /* we close the macro program. We only need to run the above code once to start per session*/ /* now we call our macro program like so.*/ %sensitivityfactoring(var1, UP, C:\path location of file, data1, C:\outputpath, newdatasetname); %sensitivityfactoring(var1, DOWN, C:\path location of file, data1, C:\outputpath, newdatasetname); %sensitivityfactoring(var2, UP, C:\path location of file, data1, C:\outputpath, newdatasetname); %sensitivityfactoring(var2, DOWN, C:\path location of file, data1, C:\outputpath, newdatasetname); %sensitivityfactoring(var3, UP, C:\path location of file, data1, C:\outputpath, newdatasetname); %sensitivityfactoring(var3, DOWN, C:\path location of file, data1, C:\outputpath, newdatasetname); %marco sensitivityfactoring( varname, UporDown, libin, datasetin, libout, datasetout);   /*comment explaining the macro program parameters above*/   /*marco (variable name, the words UP or DOWN, path to library/folder where your data are, datasetin is the name of the dataset, path to library/folder where your new data will go, datasetin is the name of the new dataset,*/   /*Macro program*/   /* define libname*/ libname datain "&libin."; /* path to library/folder where your data are.*/   /*bring data into work directory*/ data haveoriginal; set datain..&datasetin.; /* the & and period(s) (.) here are important*/ /* datasetin is the name of the dataset */ run; %if "&UporDown."="UP" %then %let Sensitivityfactor=1.1; /* we are moving the variable data up 10%*/ %else %if "&UporDown."="DOWN" %then %let Sensitivityfactor=0.9; /* we are moving the variable data down 10%*/   /* define libname*/ libname dataout "&libout."; /* path to library/folder where your data are.*/   data daatout.&datasetout.; set haveoriginal; /* we know what variable we want to change because it's name is in this macro parameter variable name "varname"*/   &varname.=&varname.*&Sensitivityfactor.; run;   /* we are done now.*/ %mend; /* we close the macro program. We only need to run the above code once to start per session*/   /* now we call our macro program like so.*/   %sensitivityfactoring(var1, UP, C:\path location of file, data1, C:\outputpath, newdatasetname); %sensitivityfactoring(var1, DOWN, C:\path location of file, data1, C:\outputpath, newdatasetname); %sensitivityfactoring(var2, UP, C:\path location of file, data1, C:\outputpath, newdatasetname); %sensitivityfactoring(var2, DOWN, C:\path location of file, data1, C:\outputpath, newdatasetname); %sensitivityfactoring(var3, UP, C:\path location of file, data1, C:\outputpath, newdatasetname); %sensitivityfactoring(var3, DOWN, C:\path location of file, data1, C:\outputpath, newdatasetname);           ... View more