This method would work on countinous as well as on negative data, just change the offset.

proc fcmp outlib=sasuser.funcs.trial;
function minus_one(number);
return (number-1);
endsub;
options cmplib=sasuser.funcs;
proc format;
value minus_one other=[minus_one()];
run;
data _V/view=_V;
set Comments;
CommentP1 = 1 + Comment;
ResponseP1 = 1 + Response;
format CommentP1 ResponseP1 minus_one.;
run;
title "Comments and Responses on blogs.sas.com";
proc sgplot data=_V noautolegend;
scatter x=CommentP1 y=ResponseP1 / datalabel=TruncName;
lineparm x=0 y=0 slope=1;
yaxis grid offsetmin=0.05;
xaxis grid;
run;