Beware of naive benchmarking

India produces only about half as much rice per hectare as China, the world's largest producer, and just about a third less than Vietnam. On the face of it - in benchmarking terms - this look like very poor performance.

However, delve a little further and you realise ... India is a very heterogeneous country, from irrigated to rain-fed areas and rice is also grown in very marginal areas. So the average productivity comes down If you look only at the irrigated areas, the yields are very high compared to any part of the world.

In China, they seem to use significantly more fertilizer, so the high yields are associated with longer-term environmental damage.

Now who has the best (long-term) productivity?