SADs (Suffering-Adjusted Days): An improved animal welfare measurement tool

1. Introduction to SADs

We are designing a new internal system for making quantitative decisions on animal welfare ideas. The system is called Suffering-Adjusted Days or SADs. It roughly represents the number of days of intense pain felt by each animal. This system is a work-in-progress that we are sharing to provide value to other animal welfare researchers, advocates, and those interested in work in this space.

It is essentially a measure of days in pain with various adjustments for:

• Intensity of pain

• Sentience 

• Welfare range

SADs are adjusted to “disabling” levels of pain on the Welfare Footprint pain scale. So 1 day spent in disabling pain for 1 human would be equal to 1 SAD.

This is to replace and improve the welfare points (WP) system that AIM has been using for the past few years. There is no easy way to convert between the old and new systems. If you are comparing our old reports to our new reports, we suggest you consider 1 SAD as similar or just a bit lower in value than 1 WP (e.g. 1 WP → ~0.8 SADs).

The new system is designed to be iterative and to grow in usefulness over time. Each time we do an in-depth look into a new farmed animal welfare scenario (e.g. farmed rodents, or farmed carp with stocking density limits applied), we will calculate the SADs in that case and add it to our database for future use.

For more questions, information or access to the draft, model please contact vicky@charityentrepreneurship.com or morgan@charityentrepreneurship.com. 

2. How SADs are calculated

Currently, SADs are calculated as follows:

SADs   =   SADs1 x w1  +  SADs2 x w2   =   S x WR x ( WF x MW x w1  +  ΔMR x PD0 x w2 )

This is a weighted average of two different estimates SADs1  and SADs2 with weights w1 and w2.

The main estimate is:

SADs1   =  S   x  WR   x  WF   x   MW

S = Sentience = Sentience estimates based on CE’s old estimates and estimates from Open Philanthropy and Rethink Priorities, weighted by our credence in each estimate. You can find the sentience estimates used in our SADs modeling here in the ‘Sentience estimates’ tab. 

WR = Welfare range = Welfare range (adjusted and not adjusted for neuron count) as taken from Rethink Priorities’ work (from the “Mixture” tabs). These are weighted by our credence in each estimate, including our credence that these should not be used on top of sentience weightings. You can find the welfare range estimates used in our SADs modeling here in the ‘Welfare range estimates’ tab. 

WF =  Welfare footprint = Time in pain and type of pain caused by different welfare issues for an average animal on a 1-4 scale where 0 = No pain, 1 = Annoying pain, 2 = Hurtful pain, 3 = Disabling pain, and 4 = Excruciating pain, using the welfare footprint’s definitions and system. They are weighted by our moral weight (MW).

MW = Moral weight = Academic, team, and expert views on the equivalence of each category of pain with disabling pain.

We put less weight on our secondary estimate. The secondary estimate works by comparing mortality rates and assuming mortality is proportional to welfare. Essentially we consider the SADs in a default scenario for an animal and then adjust up or down proportional to the change in mortality for a given intervention. So:

SADs2   =  S   x  WR x  ΔMR   x   PD0

PD0 =  Default scenario intensity-adjusted pain days = WF * MW in the scenario designated as the default scenario for that animal.

ΔMR = Change in Mortality Rate = The ratio of the mortality rate in the current scenario to the mortality rate in the default scenario for that animal.

3. Our SAD spreadsheet 

We are still working on it and are not ready to share the details of the model as we are still ironing out some bugs and errors. But currently, it looks a bit like this:

We intend to make our SADs model public in the future, so please stay tuned for that by signing up for our newsletter!