it needs to be investigated in its own right as there is not a simple onetoone relationship between cost reduction and market effect for example where a measure is implemented such that the cost reduction is fully transferred to the buyer as a pure rent for example food aid to recipients who could otherwise not buy any food in the market it does not change conditions in the rest of the market in this context it was emphasised that the concept of additionality is crucial it was shown for example in an illustrative quantitative exercise based on the oecd s policy evaluation model pem how the additionality of given quantities of food aid provided could be estimated for selected countries based on particular assumptions and parameters