champagne anarchist | armchair activist

Datawrapper’s policy on bad graphs

Datawrapper is a tool that lets you turn a dataset into a decent-looking chart within minutes. In an interview, co-founder Mirko Lorenz said Datawrapper is designed to prevent people making misleading graphs:

With Datawrapper, we try to make it as hard as possible to take data and create misleading charts with it. For example, it’s not possible to create bar charts with cropped axes. From time to time, users ask us to add this feature, but we never have and we never will. (via)

This may sound a bit paternalistic but it makes sense: Datawrapper’s philosophy is to offer a simple, robust way to quickly create a chart. If you don’t like the limitations, learn to code D3.js.

But Lorenz’ remark made me curious: would there be more design options, besides bar charts with cropped axes, that Datawrapper deems unacceptable? And are they limited to chart designs that are outright misleading, or do they more generally ban designs that result in ineffective or inaccurate data communication? Here’s an exploration of Datawrapper’s bad graph policy.

Y-axis not starting at zero
Datawrapper disapproves of y-axes that don’t start at zero in bar and column charts, but it allows them in line charts. I think this is consistent with the consensus on the topic.[1]

Spaghetti chart

I’m using the term spaghetti chart in the non-technical sense, meaning a chart with many lines that create an indecipherable mess.[2] Datawrapper doesn’t ban spaghetti charts.

Pie chart
Long the chart type we all loved to hate, the pie chart has recently been sort of rehabilitated. I think many people would now agree that pie charts are a legitimate way to represent proportions. That said, 3D and exploding pie charts are still suspect. Datawrapper allows pie (and donut) charts, but doesn’t seem to allow 3D or exploding pie charts.

Using perspective to create a 3D effect will make it difficult to compare the sizes of elements in a chart. Fortunately Datawrapper doesn’t seem to allow any type of 3D chart.

Stacked bar chart
The rehabilitation of the pie chart coincided with a renewed critique of stacked bar charts: «basic bar charts are clearly better than pie charts, but stack them and they’re worse!». Which, by the way, doesn’t mean that it’s always wrong to use stacked bar charts.[3] Datawrapper allows them.

Dual y-axes
Some charts have have a secondary y-axis, so different scales can be used in one chart (here’s an awkward example, source). There may be situations where this is defensible, but in general it shouldn’t be considered good practice. Datawrapper doesn’t seem to allow this.

Pictograms instead of bars
Some designers try to jazz up bar charts using pictograms instead of bars, forgetting to take into account that if you double the height of the pictogram, its area increases fourfold. The distortion is even worse when the pictograms are drawn to appear three-dimensional. Datawrapper doesn’t seem to allow replacing bars with pictograms.

  1. The most well-known example of y-axes not starting at zero are cropped or truncated axes which start at a value higher than zero, but there are also examples of axes starting at a negative value. Edward Tufte points this out in The Visual Display of Quantitative Information, using a chart from an annual report as an illustration: «A careful look at the middle panel reveals a negative income in 1970, which is diguised by having the bars begin at the bottom at approximately minus $4.200.000».  ↩

  2. You can make a spaghetti chart interactive, for example let users click a label and the corresponding line will be highlighted. But this may still be an awkward solution, especially on mobile.  ↩

  3. «They can be useful when the point is to show that a value is the sum of other values, but you’re only interested in comparing the totals. They also work if you only need to show one section and can make that the one on the bottom. Then the bars are comparable and work well. But just throwing values into a stacked bar chart is a bad idea», Robert Kosara argued. Here’s how Dutch minister Jeroen Dijsselbloem messed up.  ↩

Amsterdam houses on the Chinese market

In the Guardian, London mayor Sadiq Khan has announced the launch of an investigation into the effect of foreign investment on the London housing market. In Amsterdam, concerns have been voiced over super rich Russians and Chinese buying up property, although this phenomenon is probably in its infancy compared to London. Newspaper het Parool reported that 15 expensive houses have been sold to rich Chinese and Russians in 2014 and identified a canal house, asking price 6.7 million euros, that had been sold to an ‘international investor’.[1]

The Guardian article mentions, «a website that aims to pair Chinese investors with property developers overseas». If Amsterdam property is offered for sale to Chinese buyers, it might be listed there, although houses may also be sold through less transparent channels.

It turns out the site currently contains some thirty Amsterdam houses, offered for sale by Christie’s, Sotheby’s and other agents. The median asking price is about 1.6 million euros, with a maximum of 7.9 million euros. Unsurprisingly, they tend to be located in the posh areas of town: Canal Belt, Vondelpark, Zuidas. Incidentally, the website also contains quite a few houses in affluent villages like Aerdenhout.

Juwai has published lists of most-viewed cities. In Q4 2015 Amsterdam was the 4th most popular European city among Chinese prospective buyers. In Q1 2016 it dropped to position 8, which suggests the ranking is rather volatile.

Mind you, I have no problem per se with Chinese or Russians buying Amsterdam houses. I do think it’s a problem when rich people - be they Dutch or foreign - use houses as an investment object and drive up housing prices. But this is part of a broader problem, to do with issues like wealth inequality and the social housing sell-off.

While the scale of speculation and unoccupied houses isn’t anywhere near what’s happening in London, the Amsterdam city government warns that «it cannot be ruled out that such developments will also take place in Amsterdam.» But as De Groene argued, that doesn’t depend on Chinese and Russians buying up canal houses, but on what we’re willing to do about our housing market.


A practical issue I ran into was how to search a website in Chinese. In a variation on a trick I learned from Henk van Ess, I used Google Translate to look up the Simplified Chinese translation of ‘Amsterdam’. Then I searched for 阿姆斯特丹 One of the first search results was the page NLproperty, which, as you’d expect, lists property in the Netherlands. From there it was easy to find the property in Amsterdam.

  1. Parool. According to city government data (pdf), 6 houses were sold to foreigners at a price above 1 million euros in 2014, which suggests the sources quoted by het Parool have a lower threshold for expensive housing.  ↩


Exploring tax haven Amsterdam

In 2012, I mapped the geographical evolution of Amsterdam’s trust offices. Since 2006, many had changed their name or moved to a different location, resulting in four major concentrations: Zuidoost, Prins Bernhardplein, Zuidas and Naritaweg.

The other day I ran into a new map (pdf) of tax haven Amsterdam. Judging by this map, Amsterdam’s tax avoidance geography hasn’t changed much since 2012. The map was posted online by Action Aid on occasion of their AMSTERDAM TAX TOUR - THE BIKE EDITION. Sounds like fun and I would’ve have loved to cycle along, but unfortunately it coincides with a previous appointment.

Incidentally, Wired did a global tax avoidance map, which also features Amsterdam.


In 1960, 29 Dutch MPs had a trade union background. Today, nine

After the Second World War, almost one in five members of the Dutch Lower House had a trade union background (in 1956, the Lower House expanded from 100 to 150 members). Then change set in. In 1960 there were 29 MPs with a trade union background; today nine.1 The largest decline was between 1960 and 1980.

The position of workers hasn’t gotten any better since 1980 - partly as a result of government policies.2 More workers have precarious jobs, the social safety net has been reduced and workers receive an ever smaller share of the proceeds of their labour. In many sectors, deregulation and privatisations have produced cut-throat competition, at the expense of workers. Austerity has deteriorated the quality of public services and destroyed jobs.

The key task of unions is to help workers organise so they’re not powerless vis-a-vis their employers. But in many ways, politicians set the rules that govern the labour market. Therefore, Dutch unions should probably engage more actively in politics - for example by mobilising their members to vote in elections. Further, it’s important to train union members for leading positions within the union and in politics.


The analysis is based on the resumes of post-WWII members of the Lower House published on I counted occurances of the following union federation names: 'FNV', 'CNV', 'NKV', 'NVV', 'EVC', 'RKWV', 'KAB'.

Some notes:

  • I didn’t count mentions of unions affiliated to these federations - that would hardly be feasible given given how many there are and the changes that have occured over time;
  • I manually excluded a number of cases where names of union federations occured in resumes. Reasons include: the reference was to an organisation with a name that is identical to one of the union federations’ names; someone merely sat on a joint committee of a political party and a trade union; etcetera;
  • I did not include the small unions / union federations that represent high-educated professionals, but including them would have had a negligeable effect on the outcome.

I recorded the start and end date for each period any of these persons was a member of the Lower House. Then I defined periods using all those dates as partitions (I ended up with over a thousand periods). For each period, I checked how many people with a union background were members of the Lower House during that period.

  1. In some European countries, the relation between politics and the union movement is dominated by the social-democrat party. In the Netherlands, there are also many christian-democrat MPs with a union background. Their number shows a similar development as the number of social-democrat MPs with a union background. The current MPs with a union background are Harm Brouwer (PvdA, FNV), Sjoera Dikkers (PvdA, CNV), Fatma Koser Kaya (D66, FNV), John Kerstens (PvdA, FNV) Jesse Klaver (GroenLinks, CNV), Pieter Omtzigt (CDA, CNV), Michel Rog (CDA, CNV), Paul Ulenbelt (SP, FNV / NVV) and Linda Voortman (GroenLinks, FNV).

  2. That’s not to say that the background of MPs directly influenced government policy - the relationship may well be more complex.


Beautiful relief maps from Stamen

At Nathan Yau’s Flowing Data, I read that Stamen Terrain maps are now available globally, not just for the United States. Stamen uses Open Street Map and their tiles can be used with Leaflet.

One thing about relief maps is that they rub it in how embarrassingly flat the Netherlands are. For example, here’s the Oude Holleweg near Nijmegen (the nearby Van Randwijckweg was in this year’s Giro). It’s just a 70 meter height difference, but with gradients around 14% it’s one of the most challenging climbs in the Netherlands. Apparently, cyclists are not allowed to ride it downhill because that’s considered dangerous (update: I checked, it’s true, descending is not allowed). But if you look at the map, it doesn’t seem all that impressive.

Be that as it may, the Stamen Terrain maps «sure are pretty to look at», as Yau put it. Even when there’s hardly any elevation to show.