We've come to know it as " pester power" or the ability of children to pressure parents to make certain purchases.
我们已经知道这是一种“纠缠力”，即孩子向父母施压让他们购买某些东西的能力。
英语百科
Pester power
“Pester Power” or “The Nag Factor” as the phenomenon is known as in US literature is the “tendency of children, who are bombarded with marketers’ messages, to unrelentingly request advertised items”. The phrase is used to describe the negative connotations of children's influence in their parents buying habits.