Today my algo got this warning:
DEPRECATION WARNING Line 323: Morningstar is removing the 'operating_income' field on March 31, 2018. Morningstar recommends using a similar field, 'pretax_income' in its place. We are investigating the similarity of these two fields to determine the impact of the change. In the meantime, we recommend that you research these two fields yourself based on your specific needs. After March 31, the 'operating_income' field will stop receiving updates.
I tested 'pretax_income' as suggested in the warning but the data are quite different.
Then I tried
Fundamentals.gross_profit - Fundamentals.operating_expense: better but still a lot of differences.
My last and best way to replace 'operating_income' was
Fundamentals.operation_margin * Fundamentals.total_revenue.
The question is: Will be operation_margin also deprecated?
Actually there is no warning, but I cannot see the rationale to remove 'operating_income' and then leave 'operation_margin'.
@Quantopian: Any result about the impact of the change from your "investigation"? I cannot understand, why an important field as 'operating_income' will be removed.