minimal possible price process. There may exist more expensive price processes that deliver the same payoff. As we will show later on, over long periods of time a formally obtained risk neutral price can be significantly more expensive than the fair one. This paper focuses on the emerging possibility to potentially produce long dated zero coupon bonds less expensively than suggested under the classical paradigm. This permits, e.g. the less expensive production of contracts involving long dated zero coupon bonds as building blocks as in the case for pensions, annuities and life insurances.

The 4/2 Model {#sec:4over2model}
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To demonstrate the fact that in reality there may exist hedgeable long dated zero coupon bond price processes that are significantly less expensive than respective risk neutral price processes, we need some model that could capture this phenomenon when it is present in the market. In this section we provide such model, called the 4/2 model. Below we describe the 4/2 model that unifies naturally several well-known models. In Subsection \[subsecstrictlm\] we state the precise conditions under which the crucial martingale property of the benchmarked savings account fails for the 4/2 model.

The 4/2 Model as a Unifying Framework {#sec:unifying}
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In 