In my dynare code, all equations are in levels. However one equation is an infinite sum which I had to be written in log-linearized form recursively. I entered that equation in the following way for the variable say z , ln(z/zbar)=A*ln(z+1/zbar)+ ln (X/Xbar) where, A is a parameter and zbar and Xbar are steady state values for the variables z and X which I calculated by solving the model. Is this approach correct? Or do I need to log-linearize every equation in the model to make it consistent?