The implication here is that total dissaving is not only strongly correlated with corporate profits, but is directly causative.
Although he doesn’t fully specify this methods, it’s obvious that Corporate Profits is after-tax corporate profits (including foreign profits) and I was able to approximate his results using this FRED2 link.
Update: I re-charted this using the NIPA corporate profits inventory & capital adjusted data that he clearly used (CPROFIT). It doesn’t really change the outcome here, but it matches his chart more precisely.
Corporate profits is, in other words, after-tax and including foreign profits.
Savings is approximately personal savings (PSAVE) + the Federal deficit/surplus (FGRECPT-FGEXPND) (multiplied by -1 to match to shape of the profit line)
There are many issues with this analysis