There is a study assessing the working capital management components on profit. the indpendent variables are cash conversion cycle, $($CCC$)$ days payabale outstanding $($DPO$),$ days inventory outstanding, and days sales outstanding. As for the dependnet variables return on assets $($ROA$)$ and return on equity $($ROE$).$

Q: what can we say as to why ROA and ROE were chosen as dependent variables and not net operating income $($NOI$)$ or Tobins Q $($TQ$)$ for example?