The most recent report from New Zealand looked at dual candidacy and whether that happens. The report found that it doesn't. In fact, when candidates lose their constituency and end up on the list, it's almost an endgame. You find that they don't end up on the list that much longer; they tend to retire. What it found in terms of the list candidates is that if they lose their constituency seat but get a list seat, chances are they're going to be leaving by the next election.
On September 29th, 2016. See this statement in context.