自回归和分布式滞后模型：

There are many situations in which economic agents, such as consumers or producers, respond to changes in the economic environment with a time lag. The main causes of the delayed responses are the time lags in the transmission and reception of information, although the high cost of speedy adjustment can also be a factor, as can institutional constraints.

在上面的各节中，我们提到了几个经济活动的例子，这些示例通常会延迟回应，例如随着销售上涨，公司投资新的资本设备的决定，家庭决定在收入增加后增加消费支出，以及大量投资支出后公司利润的影响。

To accurately model these delays we need to incorporate lagged values of the independent and dependent variables in our model structure. Some of these models, besides being empirically accurate, can be justified theoretically as well. Simple distributed lag models, with no lagged,dependent variables may be estimated using, ordinary least squares techniques. However, dynamic models require more complicated. estimation techniques, such as instrumelital variables or iterative, non- linear least squares.

Inference in these models is straight forward and proceeds as in any standard multiple regression model.