Baird, McIntosh and Ozler have an upcoming paper in the QJE investigating the differential impacts of conditional and unconditional cash transfer in Malawi:

Starting with schooling outcomes, we find that although dropout rates declined in both treatment arms, the effect in the UCT arm is 43% as large as that in the CCT arm. Evidence from school ledgers for students enrolled in school also suggests that the fraction of days attended in the CCT arm is higher than the UCT arm. Using independently administered tests of cognitive ability, mathematics, and English reading comprehension, we find that although achievement is significantly improved in all three tests in the CCT arm compared with the control group, no such gains are detectable in the UCT arm. The difference in program impacts between the two treatment arms is significant at the 90% confidence level for English reading comprehension. In summary, the CCT arm had a significant edge in terms of schooling outcomes over the UCT arm: a large gain in enrollment and a modest yet significant advantage in learning.

The paper then gets nuanced:

When we turn to examine marriage and pregnancy rates, however, unconditional transfers dominate. The likelihood of be- ing ever pregnant and ever married were 27% and 44% lower in the UCT arm than in the control group at the end of the 2-year intervention, respectively, whereas program impacts on these two outcomes were small and statistically insignificant in the CCT arm.

……….. Our findings show that UCTs can improve im- portant outcomes among such households even though they might be much less effective than CCTs in achieving the desired behav- ior change.

Check it out here.