The 4% Rule was defined in America by Bill Bengen using US stocks and bonds records, along with US inflation. This is Bill's original essay and calculations. The study does not transpose to the UK because UK equity, fixed income and inflation levels are not the same; the principle is valid in the UK but not the calculation.

In this free white paper, we argue that Modern Portfolio Theory is an inappropriate basis for generating a retirement or other long-term income for individual investors because their main objective is reliability of income, not capital growth.

Research from the actuary Lane Clark & Peacock assessing modelling of retirement portfolios alongside consideration of relevant asset allocations for decumulation. It also outlines their thinking on why the heuristics on spending rules and portfolios need to be updated.

Research from the perspective of a mathematical theorist examining the patterns and behaviours of trust dividend payments to determine confidence levels for future projections via algorithms, and, specifically, the correlations to be found within the trusts. This drills down into the actual volatility of income to determine whether or not the term ‘risk’ is being correctly applied to income streams.

From an actuary’s perspective, the dividend returns of a pre-selected set of investment trusts are analysed to determine the mathematical relationship between demonstrable historical movements and future projections. It considers confidence levels within set bounds by calculating correlations and measuring causation effects, comparing model forecasts against actual portfolio returns.