The Bank for International Settlements has released a working paper on the sustainability of pension schemes, which suggests that changes in real returns have a disproportionate impact on service costs for pension schemes. The costs of funding defined benefit plans (where some post-employment benefit is guaranteed) are calculated to dramatically increase for minor falls in real returns and it is suggested pension fund assets be invested in higher growth markets.  Contributions will also need to be substantially increased in order to account for demographic changes and more onerous regulatory reforms.  A progressive shift from defined benefit plans to defined contributions plans (where the post-employment benefit depends on the performance of pension schemes) is expected as employers seek to limit their liabilities.  The authors recommend pension fund assets are invested in higher growth markets, investment options be restricted to avoid unintended risks and mandatory minimum contribution rates be set for defined contribution schemes.