How do farmers benefit from growing GM crops?

A recent study (Brookes and Barfoot, 2011) shows how much GM crops have benefited farmers in the rest of the world. Since 1996, farmers globally have gained more than € 44 billion in farm income thanks to GM crops, and 57% of this profit was due to increased yields. 

 
Additional reasons apart from higher yields and farm income encourage farmers worldwide to plant GM crops – see  “Why are farmers planting GM crops?”