Extension services enable farmers to take up innovations, improve production, and protect the environment. Extension shows positive effects on knowledge, adoption, and productivity. With studies showing very high (13–500%) rates of return to extension, it is a cost-effective way to improve farmer productivity and income.

Experiences with extension programmes show the positive impact that they have on productivity and farmer incomes. For instance, a programme with cacao farmers in Peru saw productivity rise from 340 to 600 kg per ha in three years.