The objective of this paper is to explore how the demand of germplasm held by CGIAR genebanks changed over time in order to assess the possible influence of the 1994 In Trust Agreements on germplasm demand. The proposed theoretic model motivates the realistic hypothesis that the consequences of the In-Trust Agreements lead to an enhancement of CGIAR germplasm utilization. Therefore the paper firstly examines the classical literature on biodiversity’s valuation and its recent developments and subsequently it investigates the origin of the agricultural biodiversity’s economic value, providing a basic conceptual framework to infer on factors determining the demand for germplasm. Two Bayesian estimation frameworks are applied to the IRRI accessions distribution’s time-series to provide formal evidence to the hypothesis, exploiting Markov Chain Monte Carlo methods, Gibbs sampling in particular. Evidence suggests that the demand variation implies a change in the genetic collections economic value, impacting therefore on their direct use search value.