So if you're asking if I think they manipulated all of that data (to produce results that just happen to agree with evaluations of similar programs implemented in other countries, including the United States), my answer would be no, not unless there is a compelling reason to believe that.
Then, you are naive.
"IFPRI evaluation can only be characterized as extremely positive."
No. A "percentage increase of enrollment over 20 percent for girls and 10 percent for boys," is not "extremely positive," especially given that the actual number of females and males populating the control group and the test group are mysteriously missing from the description of the statistical basis.
For example, if the control group included 100 boys, and the test group included 100 boys, then if 100 boys in the test group remained enrolled compared to 90 in the control group, then there would be a 10% difference in enrollment.
If the next year, the 100 boys in the test group remained enrolled, and compared with 89 in the control group, then there would be a 10%= ((11-10)/10)X 100 increase in enrollment!! However, there really was practically no difference between one year and the next.
What would be much more interesting to see would be the following ratio:
Total program cost/(#boys in control group enrolled - #boys in test group enrolled)