A researcher wants to study the unemployment rate in India. He collects yearly data on the unemployment rate in the country for the last 50 years from 1967 to 2017. He then uses an autoregressive model with 4 lags to forecast the one period ahead unemployment rate. The AR(4) model is of the form: Upper Y Subscript t equals beta 0 plus beta 1 Upper Y Subscript t minus 1 Baseline plus beta 2 Upper Y Subscript t minus 2 Baseline plus beta 3 Upper Y Subscript t minus 3 Baseline plus beta 4 Upper Y Subscript t minus 4 Baseline plus u Subscript t, where Upper Y Subscript t is the unemployment rate in the current time period and Upper Y Subscript t minus i (iequals1,..., 4) is the unemployment rate in time period tminusi