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What’s wrong with theories of change?

The phrase ‘theory of change’ is bandied around throughout the world of social action. We at Nesta use it quite a lot, and encourage organisations we fund to work on their theory of change.

When I first arrived at Nesta I tried to discourage my colleagues from using the phrase and circulated a critique. That had no effect at all. Here I reiterate why I’m sceptical of how the idea is presented, even though I’m wholly supportive of the underlying notion.

First, the positive. It must be good for any organisation to have a coherent account of why the things it does might have the effects it wants. In our ‘Standards of Evidence’ model we call this level 1: a logic model that plausibly links actions to results. A surprising proportion of projects and programmes struggle to get to this level.

What’s the problem then?

The problems come with the phrase ‘theory of change’, in which, to put it bluntly, each of the words is somewhat misplaced and doesn’t stand up to much scrutiny.

Take the use of the word ‘theory’. A theory is generally taken to mean an idea, principle or law that is separate from, and more general than, the thing being explained. So a theory of change should be general – like the theory claiming that higher income in a country tends to lead to more democracy, or that higher levels of education for girls will tend to lead to a lower birth rate, or that sending criminals into classrooms will dissuade teenagers from becoming criminals themselves. The advocates of theories of change use the word ‘theory’ in an almost opposite sense to describe a specific explanation of a specific example (albeit one that should then have predictive power), but never explain why they do so.

The next problem is the use of the word ‘theory’ in the singular form, not plural. Any serious explanation of anything in the social world should be suspect if it only uses one theory – e.g. a theory of financial incentives, or peer influences. All successful models are assemblies of multiple elements and theories. Again, I’ve no idea why the advocates chose to do this.

Even the word ‘of’ is misplaced. The purpose of theories of change is to guide action. They are in this sense theories for change, rather than of change. A theory of change is a backward looking theory in the classic social science sense. I have less of a problem with the word ‘change’, but even this is misleading. What we want an explanation for is an effect, an impact or an outcome, not the change process itself.

I admit that these comments are rather pedantic – and that most of the time the ways in which the idea of theory of change is used are helpful. But there are still other problems with the concept. The typical theory of change, as set out in many accounts, risks being misleading in two rather important ways.

The concept

One is that they tend to be far too linear, assuming that inputs lead to outputs, and that outputs lead to outcomes. This sometimes happens. But anyone familiar with systems thinking will be dubious of linear explanations, especially where complex social phenomena like homelessness, poverty or isolation are concerned. I used to advocate mapping systems to see all the links between different causes, and then to be precise about the strength of knowledge about each of those links, and about who had the power to influence them. These types of system maps provide a very useful starting point for then thinking about how a particular organisation or intervention can work within a system, but there isn’t anything quite comparable in the theory of change literature.

The second related problem is that theories of change risk squeezing out the space for learning. The advantage of the kind of systems map I just described is that they are explicit about the limits of knowledge, and where, through action, you might want to generate better knowledge about what works and what affects what. Our own use of the phrase makes this explicit as we encourage organisations to move up the ladder of evidence, generating additional knowledge about what works and why.

So the motives for wanting a theory of change are entirely healthy, and for any organisation which hasn’t thought rigorously about what it does, and what effects it has, the process of working out a theory of change is useful. But these are just starting points.

I wrote this note because I couldn’t find much debate about what is good or bad about the theory of change approach – another example of how civil society adopts ideas uncritically. Too often ideas just become fashionable and spread thanks to neat branding. It is much better to interrogate, question and then adapt by keeping the good bits and rejecting the bad ones. But where are the places, magazines, journals or websites supporting serious debate on issues of this kind? At least in the English-speaking world there’s a bit of a gap.


Geoff Mulgan

Geoff Mulgan

Geoff Mulgan

Chief Executive Officer

Geoff Mulgan was Chief Executive of Nesta from 2011-2019.

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