Results of a collaborative project involving over 28 agronomists and economists are reported. Over 800 agronomic experiments conducted in ten locations in six Asian countries comparing farmers' production with maximum yield levels of modern rice technology are analysed. Under wet season conditions, yields were raised by an average of 0.9 tonnes per hectare, but the cost of obtaining the increased yields exceeded their value in six out of ten locations. Under dry season conditions, yields were increased by an average of 1.3 tonnes per hectare, and were profitable in nine out of ten locations. High levels of fertilizer and insect control contributed roughly equally to raising the yields, but the increased cost of high insect control exceeded the value of its yield contribution in most cases. The opposite was generally true for fertilizer. One result has been that rice entomologists have reoriented their research to try and achieve more cost effective protection. There was a distinct negative correlation between the increased yield obtained by adding fertilizer above the farmers' levels and the price of fertilizer in terms of rice, dramatizing how price policies affect incentives.