Shareholder yield was designed to fix the blind spot in dividend-yield, which ignores buybacks entirely. A company returning 6% through repurchases and nothing in dividends looks like it returns nothing on a screen that only reads dividends.
Including debt paydown captures value transferred to equity holders by de-levering. The measure is backward looking, so verify that the buyback pace is continuing rather than a one-off.
Example: a $10B company pays $200M in dividends, repurchases $400M net, and repays $150M of debt. Shareholder yield is $750M / $10B, or 7.5%, against a headline dividend yield of 2%.
Related: buyback-yield, dividend-yield, share-buyback, enterprise-value