 Taking a long, long historical perspective and focusing mainly on the continent of sub-Saharan Africa. There was a view that African animal agriculture systems and African crop livestock systems weren't sufficiently well integrated. They didn't use machinery services from animals such as animal traction or cartage. They didn't use manure for soil fertility. They didn't use animals for such tasks as plowing and weeding cultivation in general. And that productivity of African agriculture could have been increased by introducing mechanization of the form of animal traction and by introducing integration of animals and crops on the same farm under the rubric of what was broadly called mixed farming. So one thing that we looked at in this book was to look at these hypotheses about the introduction of mechanization into mixed farming and sub-Saharan Africa, the extent of mixed farming. Why mixed farming occurred, why it didn't occur, where it was prevalent, where it wasn't. So we looked at such hypotheses as animal disease. Did the Setsifalai prevent the introduction of using animals and cropping? Was there a lack of mechanical skills? Was animal traction or was cultivation with machines either using animals or using diesel engines profitable or unprofitable? Were there environmental factors such as soil types and rainfall, population density and access to markets that promoted or discouraged various forms of mixed farming, mixed farming using animals, mixed farming using engines such as tractors? It's fair to say that the agricultural systems, the pastoral systems, in particular, were not very well-studied. I mean, there had been a fair amount of anthropological work done by the colonial anthropologists in West Africa and in East Africa on pastoral systems on agricultural systems in general. There was a good deal of work done on veterinary health aspects done by the colonial vets, especially the French. But as far as the basic ecology, the soils, the water management issues, the plant production issues, the possibility of introducing exotic plants, the interactions between farming systems or cropping systems and livestock systems, this was not particularly well understood. A picture of African animal and cultural systems became clear in the 70s, the 80s and the early 90s that had never existed before then. And so now this knowledge is available. It's quite a scientific achievement, although because of, if you will, environmental reasons, basically the low productivity inherent in arid areas, it's been more difficult to translate those into productivity, that new knowledge into productivity increases. Well, it gives you some idea of, first of all, what has been tried and what has worked and what has not. I mean, when Ilrad was started in the early 70s, it was thought that there would be a second generation ECF vaccine straight away. Remember, there was the old, there was the initial ECF vaccine that had been developed in Kenya in the 70s. We thought there would be a second generation vaccine, well, it's still been difficult to achieve. It was thought that within 10 years or so there would be a TRIPS vaccine, although the initial, I believe it was the two initial external reviews of Ilrad said, well, it's not working out and it may be more difficult than we thought. And still today, there isn't one. But there were very significant, but despite these, I won't necessarily call them failures, let's despite these long gestation times, if you will, there's been a lot of new knowledge on bovine immunology, as shown in the chapter by Sam Black and Cynthia Baldwin in the book. And it's shown in Sam Black's chapter on the history of TRIPS research also in the book. There's been a lot of applied knowledge on TRIPS control campaigns. The TRIPS control campaigns have been exhaustively studied. The book for space reasons doesn't do justice to all of them, but it does cause them in one of Delia's chapters on that and sort of get what can work, what's necessary for sustainability of TRIPS control campaigns in the absence of a vaccine. So there's, in the whole area of disease control, disease prevention on the vaccine side, control management on the non-vaccine side. There's been quite a substantial body of knowledge generated over the first half century of these two institutions that merged in 1995. Agriculture is not macroeconomics. Macroeconomics, you can download the data, you can run some regressions, you can do some simulation models, that's macroeconomics. You don't have to leave your house these days, you don't have to leave your library or university, but agriculture is different, you have to go out and look. You know, it's the old story of the Italian priest. The Italian priest said, well, you know, if there's an earthquake in Hawaii, I know it immediately. But if I want to know how many bicycles there are in my village, I have to go out and count them.