Last autumn, Amsterdam politicians discussed on Twitter whether the relations between coalition and opposition have changed since the March 2014 election, which resulted in a new coalition.
One way to look at this is to analyse voting behaviour on motions and amendments over the past two years. From a political perspective, proposals with broad support may not be very interesting:
For example, a party can propose a large number of motions that get very broad support, but materially change little in the stance, let alone the policy, of the government. In the litterature, this is sometimes referred to as «hurrah voting»: everybody yells «hurrah!», but is there any real influence? (Tom Louwerse)
In a sense, it could be argued that the same applies to proposals supported by the entire coalition. More interesting are what I’ll call x proposals: proposals that do not have the support of the entire coalition, but are adopted nevertheless. In the Amsterdam situation these are often proposals opposed by the right-wing VVD. The explanation is simple: Amsterdam coalitions tend to lean to the right (relative to the composition of the city council). As a result, left-wing coalition parties have more allies outside the coalition.
Let’s start with the situation before the March 2014 election. The social-democrat PvdA was the largest party. The coalition consisted of green party GroenLinks, PvdA and VVD, but the larger left-wing parties PvdA, GroenLinks and socialist party SP had a comfortable majority. The chart below shows the parties that introduced x proposals. The arrows show who they got support from to get these proposals adopted.
The size of the circles corresponds to the size of the parties; pink circles represent coalition parties. The thickness of arrows corresponds to the number of times one party supported another party’s x proposal. The direction of the arrows is not only shown by the arrow heads but also by the curvature: arrows bend to the right.
The image is clear: PvdA and especially GroenLinks were the main mediators who managed to gain support for x proposals.
And now the situation after March 2014. By now neoliberal party D66 is the largest party and the coalition consists of SP, D66 and VVD. This means that PvdA and GroenLinks are now opposition parties, but it turns out they still play a key role in getting x proposals adopted. GroenLinks initiated as many as half the x proposals.
The most active mediator is Jorrit Nuijens (GroenLinks), followed by Maarten Poorter (PvdA) and Femke Roosma (GroenLinks).
Data is from the archive of the Amsterdam city council. Votes on motions and ammendments as of January 2013 can be downloaded as an Excel file. The file (downloaded on 31 January 2015) contains data on 1,165 (versions) of proposals, put to a vote until 17 December 2014.
A few things can be said about the Excel file. On the one hand, it’s great this information is being made available. On the other hand, the file is a bit of a beast that takes quite a few lines of code to control. The way in which voting is described varies (e.g., «rejected with the votes of the SP in favour», «adopted with the votes of the council members Drooge and De Goede against»); the structure of the title changed in November 2014; Partij voor de Dieren is sometimes abbreviated and sometimes not; and sometimes the text describing voting has been truncated, apparently because it didn’t fit into a cell. Given the complexity of the file, it can’t be exluded completely that proposals may have been classified incorrectly.
The analysis (by necessity) focuses on visible influence. The first name on the list of persons introducing a proposal is considered as the initiator. In reality, it will probably sometimes occur that an initiator will let someone else take credit for a proposal.
The code for cleaning and analysing the data is available here. The D3 code for the network graphs is based on this example.