AFTER two months and three failed rounds of negotiations, Iceland has a government at last. On January 10th Bjarni Benediktsson, leader of the Independence Party, announced that he had struck a deal with two other centre-right groups. Yet his tenure as prime minister may be short. Opposition politicians are already calling for a vote of no confidence and fresh elections. And even if the coalition survives for the moment, with a measly one-seat majority, it is unlikely to last long.

Iceland is not alone in its coalition-building woes. Across Europe politics is becoming more fragmented and governments harder to form. Smaller parties, among them populists and single-issue outfits, are popping up and stealing support from the traditional powers. In the early 1980s the average number of parties winning more than 1% of the vote at each election was seven. Now it is nine. Meanwhile the share of the electorate that the winner claims has fallen from 37% to 31%, on average (see chart).

Party up

In many ways, a greater diversity of parties is a good thing. It allows more voices to be heard, and can increase citizens’ engagement with politics. But it also has drawbacks. The most obvious is time-consuming coalition wrangling. Irish lawmakers took 63 days to strike a deal after an election last March. In October Spain’s Popular Party cobbled together a minority government following ten months of political deadlock and two elections. After a 2010 ballot Belgians went a record 589 days without a government.

Such awkward coalition governments tend to be shorter-lived than those with fewer parties and clearer mandates. Since 1970 single-party majority governments in rich European countries have lasted around 1,100 days. Minority coalitions made it less than half that time.

In addition, coalitions made up of widely disparate parties struggle to pass laws. Finland’s current government, made up of two centre-right parties and the True Finns, a populist, nationalist outfit, came to blows in 2015 over a proposed health-care reform. After more than a year of negotiations and the prime minister threatening to dissolve the parliament, a deal was finally struck in December 2016. Studies suggest that this fits a pattern: the more parties there are in a coalition or the farther apart they sit on the political spectrum, the fewer laws they will pass.

Because coalition governments have more mouths to feed, they can be expensive. One paper by Kathleen Bawn and Frances Rosenbluth, both political scientists, looked at public-sector expenditure across 17 European countries from 1970 to 1998. It found that adding a party to a coalition increased spending by 0.5% of GDP. For countries with strong economies and low debt, such as the Netherlands, this may not be a problem; for countries like Greece and Italy it is.

One reason for rising fragmentation is growing inequality, explains Simon Hix of the London School of Economics. Between the mid-1980s and 2008 the disposable income of Europe’s richest 10% grew almost three times faster than that of the poorest 10%, according to the OECD, a club of mostly rich countries. As wages became more dispersed, voters’ preferences grew more polarised, with the rich supporting the status quo and the poor opposing it. Polarisation among the public begets fragmentation in parliament. At the same time the values of urbanites increasingly diverged from those of rural folk. Such splintering creates distinct pockets of voters to which smaller parties can appeal.

Another factor is plummeting party loyalty. In the 1960s roughly 10% of Britons were members of a political party. Today a mere 1% are. A similar pattern holds across Europe. Mainstream media organs once tended to support one of the two main political powers and cover only a handful of curated topics. Today politics can be more personal. An ardent green voter might read only environmental news, sharing it with like-minded souls on social media.

Some electoral systems are designed to keep smaller parties out of power, thus discouraging fragmentation. But these mechanisms are less effective than they used to be. Greece awards a 50-seat bonus to the winning party. Yet Syriza, the ruling left-wing outfit, still failed to secure a parliamentary majority after the latest election in 2015. Even Britain, which has a first-past-the-post system, was forced into coalition government after the 2010 election.

One strategy for coping with fragmentation is to form so-called “grand coalitions” of parties across the left-right divide. Such coalitions currently govern in Germany, Austria and the Netherlands. Yet this often reinforces the dynamic: voters become frustrated by the colourless centrism of such governments, and drift further to the extremes. On the bright side, this brings even more political diversity. As for the dark side of political fragmentation, Europe may simply have to live with it.