“…The nonlinear Granger causality test, which was first introduced by Baek and Brock (
1992) and further developed by Hiemstra and Jones (
1994), fits well in our context. It has been commonly applied in the literature to understand the causality relationships between, for example, oil and agricultural commodity prices (Nazlioglu,
2011), grain and livestock prices (Fiszeder & Orzeszko,
2018). The nonlinear Granger causality test is based on the following models, which generalize the linear Granger causality test:
where
and
are flexible functions for predicting
without and with the historical series of
, respectively.…”