Food waste benefits UK supply chain by up to £1.5 billion

There has been much recent coverage in the trade press about ReFood's 2020 vision campaign (see e.g. here). According to reports food waste is costing the UK £17 billion per annum. An extraordinary sum and at face value seems to offer the potential for vast savings. But is it accurate, or does it suffer from the common problem of failing fully to incorporate the opportunity costs involved in eliminating food waste?

ReFood/WRAP figures suggest that households waste 4.2m tonnes of food and 4.3m tonnes are lost in the supply chain. So roughly a 50/50 split. This means that the supply chain alone is wasting £8.5 billion every year. Wow.

But of course there is a reason that waste exists and that actors within supply chains "over-order". It is to reduce the risk of lost sales caused by having insufficient stock available. This risk is asymmetric as the value of a lost sale will outweigh the costs of material inputs, and this creates an incentive to over-order to guarantee stock availability. The lower the proportion of material input costs in output value, the greater the incentive to over-order.

For our food supply chain, I presume that the £8.5 billion figure is actually final sales equivalent. Assuming that retailers have a margin of around 15% and that the incentive is to over-order up to the point where the additional stock would outweigh the value of an additional sale foregone, this would mean that the £8.5 billion of food waste actually has a value to the supply chain of circa £10 billion. In other words, eliminating the food waste would provide £8.5 billion of savings but at the same time would lead to £10 billion of losses - an aggregate loss of around £1.5 billion.

We can therefore deduce that the presence of this food waste actually benefits the UK supply chain by up to £1.5 billion every year (given current policies and technologies) and as such is a good thing.

(This is a v simplistic approach and in reality the optimisation problem would be based on p(lost sale), which is influenced by a range of factors, including technology, logistics, timing, demand, etc and costs to consider would include waste management costs as well as input costs, etc.)

[Separately, I would argue that the £8.75 billion wasted by householders is caused by the incentive of avoiding unforeseen additional trips to the supermarket. £8.75 billion is the equivalent of 700m hours (based on median hourly wages of £12.50), or just under half an hour per week per household. If eliminating this household food waste raised time spent on food shopping by over half an hour per week then householders would lose out and the net benefits to the economy would be negative.]

New WRAP research exaggerates food waste value

I see via Edie that WRAP has published some new research examining the lost 'value' of food and packaging waste in UK supply chains (i.e. from the business sector as opposed to households). This comes to the staggering conclusion that around £7 billion is being lost to UK plc which, if addressed, could provide a significant injection to the economy through increased investment/exports/something else.

The first issue I have with the estimate is that they use average costs for estimating the 'value' of the lost food and packaging. It would be fairer and more accurate to use marginal cost data for ingredients and production costs, although I appreciate it would have been more difficult to get hold of this information.

Similarly they have included lost profit and capital expenditure in their estimates (12% of the total). This is a bit cheeky as capital spend is a fixed cost (and shouldn't be included in marginal cost estimates, as above) while absent profit is by definition not a cost (profit = revenues - costs).

So straight away we can see that their cost estimates are higher than they should be.

But the biggest issue I have with the associated headlines and rhetoric around lost opportunities for investment/the economy is that WRAP assumes that all of this 'value' can be captured at zero cost. This is utterly preposterous. The behaviour of the relevant economic agents tells us that this is not the case. Otherwise they would be doing it.

For WRAP to assume that all this waste is 'avoidable' and therefore able to be captured at zero cost is nonsense.