Jakobsen, and two fellow colleagues, turned their research into the software system RIO - which is an acronym for the Danish ‘Rentestruktur for Inkonverterbare Obligationer’ and translates as: Term Structure of Interest Rates for Non-Callable Bonds.

It was the first and - and for several years the only – program capable of estimating zero coupon yield curves for the Danish bond market. Within the first two years, almost all larger Danish banks and several pension funds were using RIO – and most still do.