How the “Election Professor” fine-tunes democracy
Theme: Tech & Democracy
For nearly 20 years, he has explained the mathematics behind Sweden’s electoral system – in interviews, opinion pieces and television studios. He has also helped change the way votes are translated into seats in parliament. Yet there are still things about the system that trouble mathematics professor Svante Linusson.
His office is located in one of KTH’s most imposing buildings. Completed in 1917 – just a few years before women gained the right to vote in Sweden – it now houses one of the people who helped fine-tune how votes are converted into political power.
“I usually say that working in these premises is a perk of the job,” says Svante Linusson.
Fascination for solving problems
You can still sense the KTH student in the professor. His interest in mathematics began with a fascination for solving problems, and that curiosity is still very much there. For years, he has worked to show that mathematics is not just abstract theory, but something deeply connected to society.
“The algorithms behind the electoral system are a very good example of that, because they determine how seats are distributed in the Riksdag,” he says.
It is a subject he has returned to repeatedly over the years. He has identified flaws in the system, warned about them – and later helped fix them.
At its core, the problem sounds simple enough: votes cast in an election must be translated into parliamentary seats, proportionally. A party that receives 5 per cent of the vote should also receive 5 per cent of the seats in parliament. But 5 per cent of the Riksdag’s 349 seats equals 17.45 – so should that become 17 seats or 18?
“So far, the mathematics is not particularly complicated. It becomes more complicated when you start discussing why one rounding method should be used instead of another in order to make the result fair.”
Different methods produce different outcomes. Sweden uses the modified Sainte-Laguë method, which Linusson describes as fair to political parties.
Close result in 2010
But the system has more layers than that. Seats are first allocated within constituencies, 29 in Stockholm, for example, and 5 in Blekinge, before the result is adjusted through adjustment seats to ensure proportional representation nationwide.
And this is where things can go wrong.
The 2010 election became a clear example. The result was so close that late-arriving votes could determine the outcome. Suddenly, the equalisation seats were no longer enough to guarantee full proportionality. Some parties ended up with more seats than their share of the vote justified, while others received fewer.
“To be perfectly honest, many political scientists do not have a particularly strong grasp of how the electoral system actually works. I had already warned that this could happen.”
The day after the election, he wrote an opinion piece in one of the morning papers arguing that the system had to be changed before the next election. It marked the beginning of his role as the media’s “election mathematician”.
He was soon called in as an expert, helping election committees calculate probabilities. In some regions, the margins were so narrow that a missing envelope containing 15 votes could potentially have affected the final result – something he was asked to analyse.
“You certainly didn’t need a mathematics professor for that. But I think it was reassuring for the people making the decisions to have the numbers behind them. Since then, Sweden’s central election authority has hired its own mathematician. Now they no longer need to consult me,” he says.
Eventually, a parliamentary committee was appointed to review the electoral system, and Linusson served as one of its experts.
One challenge remains
Today, the system has been revised. Among other changes, parties can now lose constituency seats if they receive more than their proportional share.
Linusson is now largely satisfied with the electoral system. But not entirely.
One issue remains, and it concerns municipal elections. Municipalities can influence the rules themselves by deciding whether or not to divide elections into constituencies, effectively changing the threshold for smaller parties.
“In that sense, the electoral system becomes political. It should not be up to municipalities themselves to regulate that.”
But his engagement does not stop at how votes are counted. As more and more public debate moves online, he sees new democratic challenges emerging.
“The algorithms governing social media platforms should be under democratic oversight. These companies should be required to disclose what their systems are optimising for – aggression or friendliness, for example. It is no stranger than wanting to know what is in our food.”
And if history repeats itself, that debate is unlikely to remain confined to his office for long.
Text: Anna Gullers (agullers@kth.se)