Factbox: Dutch pension pots stand out among global retirement funds

(Reuters) - The world's rich nations face a double-whammy, with ageing populations meaning more retirees -- just as low and negative interest rates make it harder for pension funds to secure the investment returns needed to fill up their coffers.Pensions typically have three pillars: a basic state payout designed to prevent people falling into poverty once they stop work; a larger slice related to lifetime earnings; and voluntary top-ups for those who can afford them.How they are organised and..