THE attempt last week to overthrow Recep Tayyip Erdogan, Turkey’s president, was at once surprising and familiar. Few had thought that the armed forces, however disgruntled, would dare to remove an elected leader who enjoys widespread support. But it was only a short while ago that Turkey suffered a coup every ten years or so, on average. The same can be said for coups around the world. They are almost always unexpected: by their nature, they aim to catch the government unawares. Yet they occur often enough. The past three years have seen successful coups in Egypt and Thailand, along with several botched attempts in other countries.

This regularity has yielded a body of research about the causes and consequences of coups, with much of it focused on their economic dimensions. There are no iron laws. Each coup is unique, laced through with political and social complexities. Still, there are certain patterns.

Start with the basic numbers. Jonathan Powell and Clayton Thyne of the University of Kentucky have built a data set of all coup attempts between 1950 and 2010. By their count, there were 457. Over that time, plotters had almost exactly even odds. Of all the bids to topple leaders, 227, or 49.7%, were successful; 230, or 50.3%, failed. But the figures have changed in recent years. Plotters appear to have honed their craft, scoring a nearly 70% success rate after 2003.

One possibility is that, as in any industry, best practice has spread. (There are suggestions that “Coup d’État: A Practical Handbook”, a study published by Edward Luttwak, has helped would-be putschists.) The basic steps—detain key leaders, take over major media outlets, control traffic arteries—are well known. In this respect, the bungling of the Turkish coup was almost as surprising as the fact that it was attempted in the first place. Yet Turkey also showed that technology is challenging established formulas. Mr Erdogan harnessed social media to rally crowds of supporters and used video-streaming to conduct a live interview with a TV station.

Coups have also become less common over the years. Their heyday was the mid-1960s, when nearly 15 took place every year. In the 2000s that fell to less than five a year. The Turkish coup was the first attempted this year. There are many possible explanations for the decline in coups, but one is economic: the world has become richer. Looking at a sample of 121 countries, John Londregan and Keith Poole, then of Carnegie Mellon University, concluded in 1990 that coups were 21 times more likely to occur in the poorest than in the wealthiest. Using another group of countries, Paul Collier and Anke Hoeffler of Oxford University found in 2007 that the risk of coups fell by about 27% as the level of income per person doubled.

By the same token, growth rates matter. Raising it by one percentage point reduces the probability of coups by 4.4%. The corollary is, of course, that slower growth raises the risk. There is no automatic threshold. Just look at North Korea or Zimbabwe, where the economies have been disastrous for years without soldiers defenestrating their leaders. But it is axiomatic that so long as an economy is thriving, coups are far less likely. In the case of Turkey most attention has been placed, rightly, on the army’s discomfort with Mr Erdogan’s tightening grip and his embrace of Islam in a once fiercely secular state. Yet it is also noteworthy that growth over the past decade has disappointed and that reformists have been sidelined in recent months.

Coup de graphs

What happens to growth after a putsch? One opinion occasionally voiced is that coups might be helpful, allowing no-nonsense leaders to dispense with endless politicking and push through smart policies. That view was heard in Egypt in 2013, and again in Thailand in 2014. But this is unlikely, according to Erik Meyersson of the Stockholm Institute of Transitional Economics, who has looked at hundreds of failed and successful coups. Failed coups have little discernible impact on a country’s growth; after short-term volatility, it quickly returns to its previous trend. Successful coups, however, do have a real impact—but only in previously democratic countries. In such places, coups lower the growth of income per person by as much as 1.3% a year over a decade (see chart). As a result, incomes eventually end up more than a tenth lower in post-coup democracies. In countries with autocratic rulers, in contrast, coups make little difference in the long run.

Coups are also associated with a range of other economic pathologies, particularly in democracies. There is a reduction in social spending, perhaps because the elite that toppled the previous leaders now seek to enrich themselves and their cronies. Financial stability also tends to deteriorate as governments rack up greater debts. Impaired legitimacy makes it harder to collect taxes, and the confidence of foreign investors seeps away.

Mr Meyersson’s explanation of why democracies fare so much worse is simple: coups are much more of a wrenching change for them. In authoritarian countries, with no mechanism for transferring power, coups are part of the natural order of things. In democracies—even imperfect ones such as Thailand or nascent ones such as Egypt—coups represent a fundamental rupture, altering the course of their development.

From this standpoint, the failure of Turkey’s coup bodes well for the economy. Whatever illusion of stability the generals might have offered, the economic costs would have been severe (to say nothing of the anger that would have welled up in society). Yet Turkey may be one case where the effects of a failed coup are much the same as those of a successful one. This is not shaping up to be a victory for Turkish democracy. Rather than reinforcing Turkey’s democratic institutions, Mr Erdogan is purging his enemies, real and perceived, and entrenching his own rule. Putsches can come in many forms.

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