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Expected Value Premium Principle


Definition

For integrable loss X≥0X\ge0, the expected value principle sets Π(X)=(1+θ)E[X]\Pi(X)=(1+\theta)\mathbb{E}[X], where θ≥0\theta\ge0 is a fixed loading coefficient: the loading Π(X)−E[X]=θE[X]\Pi(X)-\mathbb{E}[X]=\theta\mathbb{E}[X] is a fixed proportion of the mean, so the principle has nonnegative loading. At θ=0\theta=0, it is the net premium principle, Π(X)=E[X]\Pi(X)=\mathbb{E}[X].


Interpretation

The loading is a constant proportion of expected loss. Different risks with the same mean receive the same price, regardless of their dispersion.

Premium plotted against expected loss: the red line (1+θ)E[X] lies above the dashed net-premium line E[X], with the loading 20 marked at E[X]=100 and the premium 132 at E[X]=110.

The figure draws the Examples case θ=0.2\theta=0.2. The premium line (1+θ)E[X](1+\theta)\mathbb{E}[X] is a ray through the origin with slope 1.21.2, so the loading, the vertical gap to the net-premium line E[X]\mathbb{E}[X], grows in proportion to the mean: at E[X]=100\mathbb{E}[X]=100 the premium is 120 and the gap is 20. Only the mean enters, so any two risks with that mean sit at the same point. Adding a certain 10 moves the mean to 110 and the premium to 132, so the certain amount is loaded as well, which is why translation consistency fails.


Key Results

  • The principle is proportional and additive for integrable losses, even without independence.
  • It has nonnegative loading and is monotone under stochastic or stop-loss order.
  • For θ>0\theta>0, translation consistency fails: adding certain cost cc adds (1+θ)c(1+\theta)c to the premium.
  • Iterativity follows from total expectation only in the net case; repeating a positive loading generally applies it twice.

Examples

For expected loss 100 and θ=0.2\theta=0.2, premium is 120. Adding a certain 10 raises the premium to 132, rather than 130.


Prerequisites



Sources

Aliases: mean loading principle, expected value principle, expected-value premium principle Keywords: net risk premium, net premium principle, Π(X) = (1 + θ) E[X], loading coefficient θ, proportional loading Symbols: pi, theta

Last updated: 14 October 2026 08:21