p^Rr IIf The model could, ofcourse,be uscdto perlbrm and will not be oscillatory if ,2 < how econometricmodels-both sittglcIn the first two partsof this book we saw constructctt u"a multi-equation models-can be ffi;;;;;il;; variablcs' or-more of one -oJ"rt forecastthe i"ttltt and usedto explain and thcm li)r using and -ou"rn"tt* models in constructing In Part Threewe are againinterested #ff #iffilJ: i#ffi;,il;;**T1.,':1H.;:f '}ff :1""-T,lifl earlier we no longer PredlctIuIl instead we base our predictiott set of other variablesi" u tut'ttuf ituln"work; ,ot.tn o.t the past behavior of the vadable' the figure on page4 l4' considerthe time series/ (l) drawn in oi or busirtcss the historicalperformanceof someeconomic pcrlrnl)s *tri.t "" "l