The dynamics of blood donor appeals are counterintuitive

The ARCBS is appealing for blood donations. They need 22,000 in the next fortnight.

Three things are going to happen. 

People who are already blood donors will bring forward their donation appointment. Potentially, this means there will be a shortfall sometime in the future.

New donors will donate for the first time.

Lapsed donors, who have not donated for sometime will begin debating again.

The difficulty was donors is that of first-time donors only one in four goes on to donate regularly. This makes increasing the database extremely time-consuming and expensive

These dynamics of the donor appeals and increases in demand over time. The outcomes are counterintuitive

To demonstrate this, the first two slides things between the flows of donations and usage and accumulation of reserves stock.

In a normal equilibrium state, reserve stocks will be slightly higher than daily demand.

The first warning sign is a temporary drop in donations 

This leads to a decline in the reserve stock often below safety levels

It can lead to disastrous consequences if it happens twice.

The obvious solution is to have an appeal to donors and potential donors. These are usually successful.

The prblem is that the appeal pulls forward future donations leaving a shortfall in the future when donations and preserve stock decline again.

All of these dynamics are on the supply side. Sometimes there are events which can increase demand.

The difficult situation arises when there is a decline in donations and an increase in demand.