Back and forth on step length never finished


Hi Prof. Pfeifer and to all,
What does it mean when evaluating parameters in a Dynare lines “smallest step still improving too slow”,
and “back and forth on step length never finished”?
How critical is this?
I really appreciate any help you can provide.


That means your mode-finder did not terminate with a proper exit code that would suggest a minimum. That might be an issue. You need to check the mode_check plots and the convergence diagnostics.