Traditional school includes bird-in-hand theory, MM theory and tax difference theory ;

传统学派主要有一鸟在手理论，MM股利无关论、税差理论；

youdao

He held the bird gently in the palm of his hand.

他把小鸟轻轻地托在掌心。

《牛津词典》

Another temporary discount may not be what you want, but at least it is a bird in the hand.

再一次临时打折可能达不到你所希望的，但至少这是已经到手的东西。

《柯林斯英汉双解大词典》

We are always assured that the latter birds-in-the- bush will be better and cheaper than the bird-in-the-hand.

CENTERFORSECURITYPOLICY: Forgetting about the 'Saviors of Our Country'

And any cuts now are a gift that keeps on giving, with helpful compounding effects in outyears unless they are erased or undone by future legislation (always a good bet, but the bird-in-the-hand rule should apply here).

FORBES: On Government Spending, It's Time For Short-Term Thinking