摘要：Vector autoregression (VAR) methods are used to analyse the contribution of supply, demand and policy shocks to unpredictable fluctuations in the market for Australian wool. VAR procedures are compared with conventional structural econometric models as methods for decomposing sources of instability. While each has advantages and disadvantages, VAR procedures might be viewed as preferable when the underlying market structure is complex and uncertain, as it is in the case of wool. Based on the results obtained, demand shocks are the dominant source of uncertainty in the wool market in the absence of Australian Wool Corporation intervention, but intervention has blunted their effects, reducing market uncertainty and increasing the average level of prices and revenues.
