The only effective way to irradiate poverty, IMO, is empowerment of women.
Give them a control over their birth cycle so they can stop reproducing at a rate similar to rest of the animal kingdom.
And the empowerment would generally uplift the whole locality/village/town.
So, provide them with education, make them aware and most importantly provide them a means of birth control.
While mirrors might be a good idea, they might ruin the local ecology and moreover the physical maintenance and repairs of the mirrors could and would cost a fortune.
Also, if it does solve the problem it will be temporary as the mirrors won't change the lifestyle (will just make the the money factor go away, not the backward thinking) so population explosion will continue on, which will require more mirrors as the people spread across wider area.