摘要：Many analysts have claimed the record number of crop acres taken out of production in 1983 as a result of the Payment-in-Kind (PIK) program affected the already dechnmg sales offarm tractors The authors use intervention analysis, a particular form of a transfer function, to model and test for hypothesized changes in processes Three time senes (two two-wheel drive monthly sales classifications and one four-wheel drive sales classification).were modeled· as unwariate Autoregressive-Integrated-Moving-Average (ARIMA) processes These models were modified to incorporate the expected form of the PIK effects Results showed that PIK stgmficantly reduced unit sales of four-wheel drive tractors, but there was no statistical evidence of reduced sales for two-wheel drive tractors
