Seasonality and unit roots: the demand for fruits
对苹果和梨的价格与数量数据应用季节性单位根检验，并开发检验季节性周期振幅和相位变化的方法，结果对使用短期数据（季度、月度）的计量模型设定有启示。
We apply seasonal unit root tests to apple and pear price and quantity data. We then develop a method for testing shifts in amplitude andjor phase of the seasonal cycles. The results have implications to econometric specifications of models which use short-run data (quarterly, monthly).