The unifying methodology of modern econometrics was articulated by Trygve Haavelmo (1911- 1999) of Norway, winner of the 1989 Nobel Memorial Prize in Economic Sciences, in his seminal paper “The probability approach in econometrics”, Econometrica (1944). Haavelmo argued that quantitative economic models must necessarily be probability models (by which today we would mean stochastic). Determ…