Efficiency measurement has received considerable attention from both theoretical and applied economists. Although studies have been conducted on resource use efficiency in recent times in Nigeria, research focused explicitly on production factor substitution has been wanting. This book, therefore, bridges this gap in knowledge by estimating efficiency indices and elasticities of substitution of upland rice production factors in Nigerian agriculture with particular reference to Ogun State. The study concluded that rice production in Ogun State was profitable but rice farmers were not fully efficient in the use of resources. The largest single substitution possibility was between labor and fertilizer inputs, representing the main alternative methods by which farmers could raise per hectare yields. This book shed some light on application of Seemingly Unrelated Regression Estimation method (SURE), Allen Elasticities of Substitution (AES), Stochastic Frontier Production and Cost Functions to the measurement of efficiency indices and elasticities of inputs substitution. The book will be very useful to students of agriculture, lecturers of production economics and policy makers.