Randolph: I'd like a phonecard, please erectile dysfunction treatment uk lanka In their stability studies, IFS show that background factors, such as education and income, account for 42 per cent of the stability gap between married and cohabiting couples. The remaining 58 per cent of the gap is mostly down to relational issues, such as whether the birth was planned, and the quality of the relationship. IFS claim, without foundation, that these factors have little or nothing to do with marriage.