Before carrying out econometric estimation of our model it is important to investigate the
time-series properties of the variables included in the model. Augmented Dickey-Fuller
(ADF) ‘t’ unit root test results are presented in Table 1 below and suggest that the null
hypothesis of a unit root can be rejected for all the variables, except for growth in credit to
the economy, where the unit test results are borderline and ambiguous. Data on real GDP was
seasonally adjusted using the TRAMO/SEATS seasonal adjustment procedure (Franses and
Fok (2005)). All the variables are measured in terms of percentage changes over the previous
year, except for the interest rate, where the end-of-period refinancing rate is used (given that
this variable appears to be stationary; see below).