scholarly journals Conditional Granger Causality and Genetic Algorithms in VAR Model Selection

Symmetry ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1004
Author(s):  
Vasile George Marica ◽  
Alexandra Horobet

Overcoming symmetry in combinatorial evolutionary algorithms is a challenge for existing niching methods. This research presents a genetic algorithm designed for the shrinkage of the coefficient matrix in vector autoregression (VAR) models, constructed on two pillars: conditional Granger causality and Lasso regression. Departing from a recent information theory proof that Granger causality and transfer entropy are equivalent, we propose a heuristic method for the identification of true structural dependencies in multivariate economic time series. Through rigorous testing, both empirically and through simulations, the present paper proves that genetic algorithms initialized with classical solutions are able to easily break the symmetry of random search and progress towards specific modeling.

2013 ◽  
Author(s):  
Χρήστος Μπούρας

Nowadays, Granger causality tests are standard tools to investigate causal relationships between financial and economic time series. Econometric advances in the field have shown that the causal relationship between two variables is not invariant to the integration and cointegration properties of the processes nor the relevant information that is available and included in the analysis. Hence, various notions of Granger non-causality are developed in the context of linear bivariate or multivariate stationary or nonstationary discrete time processes. Several of these causality concepts are reviewed in this thesis. Their extended concept is contrasted to the standard Granger causality concept. A wide range of causality tests have been used to investigate the independence between the second moments of the time series. There is currently much interest in testing causality-in-variance by policy makers, portfolio managers, and academic researchers. […]


2014 ◽  
Vol 6 (2) ◽  
pp. 237-273 ◽  
Author(s):  
Tucker S. McElroy ◽  
Agustin Maravall

AbstractWhile it is typical in the econometric signal extraction literature to assume that the unobserved signal and noise components are uncorrelated, there is nevertheless an interest among econometricians in the hypothesis of hysteresis, i.e. that major movements in the economy are fundamentally linked. While specific models involving correlated signal and noise innovation sequences have been developed and applied using state space methods, there is no systematic treatment of optimal signal extraction with correlated components. This paper provides the mean square error optimal formulas for both finite samples and bi-infinite samples and furthermore relates these filters to the more well-known Wiener–Kolmogorov (WK) and Beveridge–Nelson (BN) signal extraction formulas in the case of ARIMA component models. Then we obtain the result that the optimal filter for correlated components can be viewed as a weighted linear combination of the WK and BN filters. The gain and phase functions of the resulting filters are plotted for some standard cases. Some discussion of estimation of hysteretic models is presented, along with empirical results on an economic time series. Comparisons are made between signal extractions from traditional WK filters and those arising from the hysteretic models.


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