The factors included in the selection equation generally increase the likelihood of IT outsourcing. Our results also suggest that firms are not homogeneous in the economic gains they accrue from IT outsourcing. Firms with high propensity to จัดจ้างคนภายนอก receive significant benefits, gaining a productivity improvement of as much as 6 percent. In contrast, firms with lower propensity for outsourcing receive few if any productivity benefits.