269 – Violence and economics 1

There is clear evidence that violence within and between human societies has decreased dramatically through the course of human history. What are the links between economics and this most-welcome development?

I remember thinking that I was very lucky when I was about 11 or 12 years old, because I felt that the world was on a pathway to improvement. I was glad to be living now, rather than earlier in history, because medicine and technology were clearly advancing, but also because I felt that people were generally getting better – kinder, more inclined to offer international aid, more opposed to war.

The idea that people are getting better might seem like childish wishful thinking, but it turns out there was something to it. So says Steven Pinker in his extraordinary 2011 book, The Better Angels of Our Nature: The Decline of Violence in History and its Causes.

Pinker was already one of my favourite authors (How The Mind Works is wonderful), but this book is really special. I can’t recommend it highly enough. It is enthralling, surprising, entertaining and even inspiring, over the course of a weighty but highly readable 800 pages.

Reductions in violence have been documented on every time scale, from millennia to recent decades. Pinker documents how every form of violence you can imagine has declined: murder, violent punishments, torture, mutilation, slavery, rape, genocide, war and more. Beneficiaries have included women, children, family members, neighbours, strangers, homosexuals, prisoners, slaves, animals … everybody, really.

violence3As Pinker observes, “It is easy to forget how dangerous life used to be, how deeply brutality was woven into the fabric of daily existence”. The good old days were, in fact, shockingly violent.

The declines in violence have been huge in magnitude. Acts of violence that we would consider unthinkable were once commonplace and unremarkable. To quote a few of the many statistics provided, in pre-state societies, around 15% of people were killed by other people; in early city states this had dropped to 5%; and the current value in Europe is around 0.001% per year.

Many different factors have contributed to this outcome, some rather surprising. I was interested that some of the reasons identified by Pinker relate directly to economics.

He argues that one of the biggest contributing factors has been “gentle commerce” – voluntary trade between willing buyers and sellers. If your way of acquiring goods is take them from your neighbours by force, then the system is a zero-sum game, meaning that there is a fixed amount of good stuff available, and if someone gets more of it, someone else must get less. If in the course of taking your neighbours’ goods you also kill them, the system is very much a negative-sum game. But if you trade, it becomes a positive sum game, with everybody better off.

The gains from trade make it more likely that people will choose to leave their neighbours alone to produce good stuff for trade, rather than choosing to raid and perhaps kill them.

Trade brings you into direct contact with a broader range of people, and you can learn that they are not the ogres you’ve been led to believe. The process of negotiating particular trades encourages each player to take the other’s perspective. It may lead to respectful consideration of the other’s interests, if only because it becomes in your interest to do so.

This virtuous spin-off from trade, including from “globalisation”, is something that very few people seem to be aware of. No doubt there are some negative aspects of globalisation, but this perspective on violence adds a huge positive to the more obvious positive of increasing general prosperity.

The evidence for reduced violence resulting from trade is strong. For example, statistics show that countries that trade with each other are much less likely to go to war. Countries that have relatively high levels of trade have experienced less genocide and less civil war.

Interestingly, it appears that increased wealth per se (which would result from the trade) may not be the main factor driving reductions in violence. Pinker shows that the evidence about the effect of wealth is mixed; its correlation with violence tends to be low. For example, the number of lynchings in southern US states declined exponentially in the first half of the 20th century, without deviations downwards for the roaring 20s or upwards for the depressed 30s.

So if it’s not wealth, it must be the act of trading itself. That’s a remarkable and important insight. Given that trade has this unintended positive consequence that benefits us all so much, it’s ironic that some people see commerce and trade as undesirable, or even immoral.

Further reading

Pinker, S. (2011) The Better Angels of Our Nature: The Decline of Violence in History and its Causes, Allen Lane, Penguin, London.

268 – Conservation agriculture in developing countries

Is “Conservation Agriculture” really a win-win for farmers and the environment? It reduces the losses of soil and nutrients from agricultural land, but are farmers who adopt it better off or worse off? In asking this, my focus is on developing countries, where soil erosion remains a serious problem.

Soil erosion reduces farmers’ livelihoods, but also causes off-farm damage, particularly to rivers, lakes and dams, and “Conservation Agriculture” has been promoted as a solution. A particular Conservation Agriculture (CA) package of three farming practices has been widely promoted in developing countries as a win-win option for farmers and the environment. It consists of zero tillage, retention of crop residues for soil cover (mulching), and rotation of cereal crops with legumes, which fix nitrogen and so increase soil fertility.

Something close to this package has been widely adopted in North America, South America and Australia, but its adoption by poor farmers in Africa and South Asia has generally been disappointing, despite years of active promotion by international organisations.

Does this mean that poor farmers can’t recognise a good thing when they see it, or is the problem that benefits of Conservation Agriculture to these farmers are not sufficient to outweigh the costs? Given the massive differences between small subsistence farms in southern Africa and large commercial farms in North America, we should be open to the possibility that a practice could be very attractive to one group of farmers but not the other.

Photo: Marc Corbeels

Photo: Marc Corbeels

In 2012 I was invited to review the evidence on the economics of Conservation Agriculture in Africa and South Asia, and to present my findings as part of a workshop on Conservation Agriculture held in Lincoln Nebraska that year.

Part of the motivation for the workshop was to try to address issues of controversy about Conservation Agriculture in developing countries. Some people had been critical of what they saw as promotion of CA as a silver bullet solution without sufficient consideration of circumstances where it did and didn’t work for farmers. Others hit back at these criticisms and defended CA as the best available option.

The workshop marshaled the evidence on various facets of CA. The results have recently been published in a special issue of the journal Agriculture, Ecosystems and Environment. All the papers can be accessed for free here.

Looking at past literature on the economics of CA for poor farmers, my co-authors and I found that there wasn’t all that much literature, but what there was tended to indicate that CA (or its components) should be economically attractive to small farmers. However, looking critically, little of this evidence was based on sophisticated analysis. Many of the economic models used seemed too simplistic to be reliable. 

So we set out to build a model of our own and apply it to a case study in northern Zimbabwe. Marc Corbeels from CIRAD joined the team, providing his data and extensive experience for the case study.

A key finding is that the farm-level economics of CA are highly case-specific. In some situations it is competitive with traditional agriculture, but in others it falls far behind. Organisations promoting CA need to be quite careful and discriminating about where it is actually a viable strategy if they are not to waste their own and farmers’ resources.

We didn’t find any scenarios where CA was substantially better than traditional agriculture. Where it was better, it was only slightly better, but where it was worse, it was sometimes dramatically worse. This would be important to farmers who are worried about risk.

CA tends to be more attractive for larger, wealthier farmers and to be much less profitable for the smallest, poorest farmers. No wonder many of them have been reluctant to adopt it.

There are several elements that can reduce the benefits of CA for small farmers. One is that zero tillage can increase the number of weeds in the crop. This either reduces crop yield or requires additional effort for weed control. A second factor is that some of the benefits take about a decade to kick in (increased yields from zero tillage combined with mulching). The poorest farmers might not be able to afford to look that far ahead when they make their farming decisions. Thirdly, crop residues may not be available for mulching. They may be harvested to feed to livestock, or in some cases farmers cannot keep other people’s cattle off their crop residues even if they want to. (The community doesn’t allow it, and there are no fences anyway.) Fourthly, legume crops may or may not be profitable enough to be worth including in the rotation. It depends on their yields and sale prices.

Some extension programs have emphasised the importance of farmers adopting all elements of the CA package. This is quite naive, as full adoption of farming packages rarely happens anywhere. Farmers almost always pick and choose the elements that they think will work for them, and leave the rest. We found that the economics tend to favour this approach in the case of CA – partial adoption tended to be more attractive than full adoption.

So, overall, this is one of those cases where the farm-level economics pose a barrier to changes that people would like to see, at least in some cases. There are good and bad ways to respond to this information. The bad ways include ignoring the information and continuing to promote CA in an untargeted way, or thinking that the adverse economics could be overcome by better or more intensive efforts to promote CA. The good ways include using the information to target CA promotion to situations where it is likely to be adoptable, and redoubling efforts to develop more appropriate soil conservation practices for situations where it is not. In some cases it might be feasible to subsidise CA to increase its uptake, but this won’t overcome adverse economics unless the subsidies can be maintained indefinitely. If they are to be maintained indefinitely, we would want to have confidence that the system will result in large enough reductions in the off-farm costs of soil erosion. 

Further reading

Pannell, D.J., Llewellyn, R.S. and Corbeels, M. (2014). The farm-level economics of conservation agriculture for resource-poor farmers, Agriculture, Ecosystems and Environment 187(1), 52-64. Journal web site (access to the paper is free) ◊ On-line video presentation ◊ IDEAS page for this paper