I’m in Melbourne for the conference of the Australian Agricultural & Resource Economics Society (in fact, I’m currently President-elect of the Society. There have been a couple of great papers on long-term food supply from Phil Pardey and Tom Hertel. So, this seems like a good idea to write down some thoughts about (what ought to be, at any rate) the central issue of agricultural economics – whether the global food system can produce enough food for the world and deliver it to those who need it. I’m hoping to refine this in response to comments – I’ll mark major changes but will otherwise adjust as I go.
Can we feed the world? Will we?
The world’s population is rapidly approaching 7 billion, of whom around 1 billion regularly go hungry. UN projections suggest that the world population is likely to peak at around 9 billion in 2050 (though this number could be in a range from 8 to 10 billion). So, if nothing else changes then to feed those currently hungry and supply the current average to the extra 2 billion or so, we would need to increase global food output by 50 per cent over the next 40 years. The good news is that, based on 20th century experience, that ought not to be hard. The required rate of growth of output is 1 per cent a year, while the rate of multifactor productivity growth in agriculture has been about 2 per cent a year.  So, if historical rates of productivity growth continue, and other demands were unchanged, the problem of feeding the world can be solved with our existing arable land and with a continued decline in the number of people working in agriculture.
That was the good news.
The bad news comes in two parts.
First, there are a lot of reasons to think that productivity growth may have slowed, and is likely to slow further. These include
* Public R&D efforts have declined, and the private sector hasn’t been an adequate substitute. GM crops (largely the product of private companies) have some benefits, but haven’t yet been the panacea that is sometimes claim
* Some agricultural systems (most fisheries, agriculture in sub-Saharan Africa, a lot of irrigation) have been operated on an unsustainable basis
* Energy is a significant input (though not as important as is sometimes supposed) and energy costs are bound to rise
* Efforts to mitigate climate change may reduce output and/or productivity
* Climate change will have a net adverse effect on productivity, particularly if warming exceeds 2 degrees
The second part of the bad news is that there will be more demand growth mainly from:
* People in middle-income countries who want to eat more meat and fruit/vegetables and less rice and wheat
* Biofuels either derived from food products or competing with agriculture for land
Taken together, these problems make the task of feeding the world much more difficult, but not impossible. To list some of the obvious responses
* The decline in public R&D spending can and should be reversed, and there is plenty of room for more private efforts such as those of the Gates Foundation – the sums involved are tiny relative to total world income
* Huge improvements are possible in Africa from better education, communications, transport, adoption of modern practices and technology, along with some focused R& D efforts. The problems of irrigated agriculture are fixable, as my work on the Murray-Darling Basin has shown. Unsustainable fishing can be replaced, to a substantial extent by aquaculture, as discussed in this Scientific American article.
* Currently, around 30 per cent of food output is lost to various forms of waste. Some of this is inevitable but much, particularly in distribution chains, could be avoided
* People in developed countries often eat more than is good for them, and the wrong kinds of foods. A simple shift from (grain-fed) beef to chicken would require less grain as feed, cut methane emissions and promote better health
For an economist, it’s natural to consider the role of prices in this. If demand grows faster than supply at current prices, then prices will rise. Some of the resulting adjustments, such as an increase in inputs to agriculture, and more expenditure on R&D will be broadly beneficial. Others, such as lower consumption in poor countries (demand for food in rich countries is not sensitive to prices) will not. Broadly speaking, people on low initial incomes will eat more (or less) food if their income grows faster (slower) than food prices. So, a more equitable distribution of global income would mean less people going hungry, even if the rate of growth of productivity slowed down.
I’ll try to write some more later, but my main message is simple. We can feed the world if we make the right choices. There is no greater moral obligation facing the world as a whole and particularly those of us who are well-fed and live in wealthy countries.
fn1. I’m assured that this position doesn’t call for administrative skills, which I conspicuously lack, as evidenced by the fact that I previously had two instances of footnote 1.
fn2. That shouldn’t be surprising, if you think about it. Food supply per person grew substantially over the 20th century, which implies that production growth outpaced population growth, and most of the production growth was due to productivity, not extra inputs. Population growth is slowing, so if productivity growth continues at the historical rate, the growth in food per person will accelerate.