KnowraWald's equationLinked fromLinked fromThe 2 pages that link to Wald's equation, each with the reason it gives.All 2Related 1Compared with 1Optional stopping theoremCompared with: It resembles optional stopping but concerns sums of independent increments and has its own hypotheses.Law of total expectationRelated: It is a specialized expectation identity closely connected to conditioning on the random count.