health economics, the WASH sector

Economist-engineers and public health economists: is WASH economics a “field”?

Is WASH economics a ‘field’?

This post explores ways of breaking down the “field” of WASH economics. On the one hand, one can argue that WASH economics doesn’t exist as a coherent field. After all, most people actually working on WASH economics questions are in the field of engineering and/or public health. There are fairly few people with an economics MSc or PhD who are working on WASH. I doubt many people self-identify as “WASH economists” in the way that health economists or environmental economists do.

On the other hand, one can argue that disciplinary boundaries are unhelpful in relation to a subject like WASH, which defies being put in a disciplinary box. Getting WASH services right often involves building stuff well, proper consideration of the underlying resources, reliable prevention of pathogen transmission, changing people’s behaviour, and doing all that with the right incentives, prices and funding/financing model. So WASH economics exists in the same way that public health engineering exists.

Personally, I would argue that WASH economics does exist as a field. However, it requires a little more shaping and communicating in the coming years to make it into a coherent one. Who cares what disciplinary background someone has as long as they’re solving a problem by (i) asking and answering the right question, (ii) using the right method, and (iii) doing a good job of it?

If an engineer is looking at preferences for different water services, and using economic methods to do so, then they are doing WASH economics. I can point to many recent papers that go in this box. Many are good or excellent, though definitely we can raise the bar by interacting more with each other.

How to divide up WASH economics sub-fields?

I already explored definitions of WASH economics in this post, going with “the study of how people make decisions about the allocation of scarce resources in the delivery and use of WASH services.” Within this there are many sub-fields. Below is my current way of sub-dividing it, drawing strongly on how my colleagues at the Centre for Health Economics in London (CHIL) at LSHTM divide up our work into themes.

  1. Economic evaluation – including work on resource use and allocation (e.g. costing, cost-effectiveness analysis, cost benefit-analysis), the valuation of outcomes, and broader priority-setting questions such as how to include equity in decisions.
  2. Economics of service providers and systems – including work on funding and financing, the role of government in providing WASH services, and the regulation of markets for WASH services. This is a broad area that would include questions of production and pricing (e.g. tariffs and subsidies), as well as the interaction of demand and supply at both the provider and sector level. Or, as is de rigeur, looking at the ‘WASH system’ as a whole.
  3. Policy evaluation – including work on attributing impact (of any kind) to WASH interventions that use economic-based methods. There is a lot of cross-over with epidemiology / public health and “implementation science” here, but some methods/questions are more economic than others.
  4. Choice and behaviour – including work on understanding the choices people make between different behaviours, products and services. This would include studies of demand drivers, preferences and willingness to pay. It may encompass work using behavioural economics or discrete choice experiments.

I hope to write a post exploring each of these in more detail another time.

What are her preferences for toilet options? Are options cost-effective? How much is she willing to pay? 

An aside on disciplines

WASH research is not unique in often requiring multiple disciplinary inputs to be successful. Many of those working on health economics, for example, have backgrounds in statistics, medicine, mathematical modelling and epidemiology. Often these other disciplines are in fact required in order to answer questions properly. It is practically impossible to do many types of economic evaluation of a vaccine or a tuberculosis intervention without involving modellers, for example. Likewise, it can be hard to know whether a change in a health outcome is clinically relevant in a given population, without asking a medical doctor.

The same would apply to doing an economic evaluation of a complex sewer intervention without involving people who know how the system works. Some decisions that look odd to an economist may make absolute sense to an engineer.

While there are trained economists who work consistently on WASH, there are others who delve in and out of many sectors. Some of these, perhaps, do not truly attempt to understand WASH before employing their standard methods toolbox (which may not be appropriate to the question at hand). They might answer the wrong question entirely. Worse, they might answer a question that public health people already answered 5 years ago but they didn’t bother to read the literature properly.

But these people are few. My point is that it would be helpful to have far more trained economists deciding to work consistently on WASH over a long period. Economists who’ve entered WASH like Britta Augsburg, Molly Lipscomb and Dean Spears (and many of the r.i.c.e. team) have added lots of value to the sector. Likewise there are those with a ‘harder’ science background like Meera Mehta (architecture) and Marc Jeuland (engineering) who have all but switched to economics. We need more of both these kinds of people.


Lots of people work on WASH economics without considering themselves economists. This is great and to be encouraged. While it is something of a cliché, we do need to break down boundaries between fields and borrow methods from each other. We also need to improve the quality and quantity of work on WASH economics, both by those who are economists and those who are not. For this, it would be helpful to have (i) more trained economists deciding to work consistently on WASH, and (ii) a more coherent dialogue around WASH economics.

2 thoughts on “Economist-engineers and public health economists: is WASH economics a “field”?”

  1. WASH economics is a field that has attracted my interest for quite some time; however, with little opportunities to learn and explore. I do a lot on WASH and strongly feel that the outcome of my research could make more sense when interpreted by economic indices. I need help in this regard.


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