Better paid leave for new parents is long overdue in the United States, and executives must lead by example to persuade hard-working, vacation-averse Americans to take advantage of such a benefit, family and employment experts said on Monday. Software maker Adobe Systems Inc (ADBE.O) on Monday became the third company in a week to expand its benefits, doubling maternity leave to 26 weeks to increase diversity in its workforce and give parents more time with their newborns.