This post is a part of the GroupLens Iron Blogging effort, so take that for what you will.

I’ve been thinking about systemic accountability recently: *how
can we hold systems accountable to a set of expectations?*

In Ecology, the ecological systems (or, you know,
*ecosystems*, I guess) they study exist in a world where they
need to be valued by humans for conservation to occur. One framing for
this value is Ecosystem
Services, which, as I understand it, has been pretty significant as
a conservation argument for the preservation of some ecosystems.

Broadly, ecosystem services give ecologists a way to talk about the specific things that ecosystems do, and actionable metrics on which to gauge what “value” the ecosystem provides.

When we think about sociotechnical platforms, a different set of
metrics might be important, but it seems useful to think about
*what* and *how* the platform or system is producing or
providing.

There are straightforward approaches to some kinds metrics, specifically for inequality (like the Gini coefficient, or the lesser-known Theil Index), but in a geographic context, these, like most other statistical measures, break down because of Tobler’s First Law of Geography, and the spatial auto-correlation that comes from it.

However, the Theil Index is decomposable,
which means that it is an average of weighted subgroups, plus the
inequality within these subgroups. Spatially, one could use the spatial
autocorrelation (using something like a standard neighbors-weights
matrix that reflects how related neighbors are to each other) to define
subgroups, and compute spatially distinct subgroups^{1}.
This decomposability means that we can derive the amount of inequality
within each subgroup, and how much each subgroup contributes to overall
inequality.

More broadly though, this seems like it also gives us a
straightforward metric through which we can start understanding *how
equal the platform is spatially*. Inequality metrics are often used
for things like housing, or income inequality, but what about
sociotechnical platforms that interact in the physical world? How does
this metric enable us to hold platforms accountable to geographic
equality? What does that sort of transparency and accountability look
like?

In a follow-up post, I hope to have an example of a spatial version of the Theil index, because I think this might be an interesting design direction.

I’m glossing over some details here because I am not intimately familiar with the math.↩︎