Bryanna is correct that mono-lingual teachers face diminished opportunities wherever bi-lingualism takes hold. So might mono-lingual government employees and politicians.

In Canada, many federal offices, even in Anglophone provinces, legally require proficiency in both languages of the officially bi-lingual nation.

Quebecers are much more likely than those from other provinces to speak both English and French. I am told this has led to Quebecers getting a disproportionate number of federal Government jobs.

Note the preponderance Quebecers among recent Prime Ministers. Vincente Fox for President anyone?