I am studying the relationship between X and Y using linear models. Both are composed of a left and right scalar value, and I'm interested in the relationship between both the totals and ratios for each one. My first thought is to create two linear models:
yratio = yright/yleft
ytotal = yright+yleft
xratio = xright/xleft
xtotal = xright+xleft
yratio = B0+
B1xleft+
B2xright+
B3xratio
ytotal = B0+
B1xleft+
B2xright+
B3xratio
Is this sensible, or is there a better systematic approach? I'm having trouble searching for this, but it seems like a reasonably common problem. My thought is that while my models are over parameterized in the sense that while the ratio can be expressed in terms of the left/right values, that can't be achieved with a weighted sum, and it is reasonably plausible (for instance) that ytotal is best predicted by xratio