Why do we use JMP estimates on WASHwatch?

If you look at the bottom of any country page in WASHwatch, you’ll see two numbers, giving the percentage of the population of that country who have access to water and the percentage who have basic sanitation.

These numbers have recently been updated (we will be updating the site shortly – watch this space!). And this has led to much discussion about the merits of these estimates. Ian Ross has a very thorough blog-post arguing the merits of the JMP estimation method.

I’ll not rehearse his arguments here, and I don’t disagree with what he says, but I’ll expand on two key questions I think his post has raised.

The main criticisms of global estimates are

1) that they are useless – you can’t make WASH investment or policy decisions in Uganda based on JMP estimates*

2) that they are extractive – they require costly data collection but are of no value to the people who provide the data

These are both valid points, but they are not unanswerable.

Do we need global numbers?

The point of JMP estimates is to be able to compare levels and trends between countries; if that is not desirable, the details of the method are immaterial – we should just stick with country level information.

WASHwatch.org is based on the premise that inter-country comparison is of enormous value. That highlighting where a country is performing poorly compared to its neighbour can spur that government to greater action.  That identifying the countries and regions of greatest need can allow international aid to be well targeted, and help campaigners to know whether it actually is.

Whether donors choose to use the data to best effect is a secondary question – we can’t know if they are off target, or demand that they do better, if the comparable data on need do not exist.

The usefulness of the data is only a problem if you are looking at global estimates as a service provision tool, akin to Water Point Mapping or Utility data. But this is not their purpose – these data are political. They tell us (comparably!) where the need is high, and where changes have been slow to materialise.

They also provide a benchmark. If there is a wide difference between a recent survey and the JMP estimates, this provokes a question – has a recent government initiative had a massive impact? Has a terrible disaster destroyed a lot of services? The difference from the normal is thrown into relief and invites a closer look.

So yes! We need these numbers.

Can we afford these numbers?

One of the most important features of the JMP estimates is that they are incredibly cheap – all the data on which they are based is already being collected, for national purposes. All that has to be done is to ensure that wherever a survey looks at water and sanitation it includes a few basic, comparable questions, and to collect all the surveys that have ever been taken and extract the relevant data.

This is not easy, but it’s a hell of a lot easier than going annually to every country in the world and observing every water connection. This is a good example of ‘aggregating up’ to form global estimates, rather than modelling global estimates and then generalising down to country level.  For a reasonable, methodologically transparent and consistent estimate of global WASH poverty, the JMP data is an absolute bargain!**

As Ian and others commenting have pointed out, we need different data for different purposes, and we must cross-reference and triangulate as much as possible to ensure reliability, precision, and to draw the most effective policy conclusions. But throwing out a cheap and politically useful piece of global analysis because it doesn’t do everything we like, would be a terrible folly.


* This seems to be the crux of the objections around functionality – the surveys do measure functionality in the sense that the source currently being used must be functional, but they don’t account for whether the same source will still function in six months.

**  It is worth noting that the only affordable way for JMP to provide more credible estimates that take functionality, quality, proximity and all the other facets of access into account is for these data to be collected at national level. They are advocating for this in the post-MDG monitoring proposals, but they cannot be expected to collate and analyse data that no-one is yet collecting, and to collect it themselves would be exactly the kind of  eye-wateringly expensive and extractive study we want to avoid.


One thought on “Why do we use JMP estimates on WASHwatch?

  1. Ben

    As the technology improves and more data sources become available, we can continue to expand what data we include in JMP estimates. I think your point that JMP takes country level data and aggregates up is brilliant- and a place where we can begin to grow our data. If 8 or 12 countries have national, georeferenced data for rural water supplies, why not include it? JMP already has select water quality reports and data for a limited number of countries. We should encourage more of this type of data aggregation and sharing. After all, the end goal is for better country-level and cross-country analysis of coverage. We don’t have to throw the baby out with the bath water- the baby is just growing up! Tracking the MDGs has changed in the last 13 years, and our monitoring systems should be improving as well. Maybe it’s time for JMP v2.0.


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