Is there a way to auto-fix the source column width in the exported bilingual file?

Dear Studio 2015 users,

For some reason the bilingual files I export for the editor always have source text column much narrower than the target text column.  I don't know what causes this, but it's a little inconvenient for me to manually adjust the source column before sending the file to the editor.  Is there a setting somewhere in Studio that I can adjust to fix this trivial issue?

Thank you for your help!

Chunyi