The OECD-FAO Agricultural Outlook provides mid-term projections of global agricultural markets simulated by the AGLINK-COSIMO model. While the projections typically present a deterministic outlook for markets that are conditional on a set of assumptions, recent experience of highly turbulent markets has renewed interest in quantitative assessment of price volatility by stochastic simulations using the AGLINK-COSIMO model. Improvements in the methodology of stochastic analyses are pursued and implemented. As an application, the impact of crop yield shocks on price volatility is studied. Since the concurrent reduction in production in different countries is deemed as one of the factors of the price spike in 2007/08, the contribution of correlation of yield shocks to price volatility is measured. This paper shows that correlation effects account for a significant portion of price volatility for coarse grains and wheat.