"The current macroeconometrics literature has proposed two ways to confront general equilibrium rational expectations models with data. The first, an estimation approach, is the direct descendant of the econometric methodology proposed 50 years ago by Haavelmo (1944). The second, a calibration approach, finds its justification in the work of Frisch (1933) and is closely linked to the computable general equilibrium literature surveyed e.g. in Shoven and Whalley (1984)."