BIG BABY STEPS: Nearly everyone points to tuition as a barrier to college completion and student success. (Jason Calacanis recently crunched the numbers on paying off a $100K-$250K degree.) But some economists think the problems start much earlier. Studies from Univ. of Chicago economist James Heckman and other researchers suggest that achievement gaps in math and reading can be traced back to pre-K preparation, giving NYTimes writer Eduardo Porter reason to believe that "Investments in Education May Be Misdirected." Cognitive gaps between children from different backgrounds persist in later ages, and "If education is supposed to help redress inequities at birth and improve the lot of disadvantaged children as they grow up, it is not doing its job," says Porter. He also adds, "...no amount of money or teacher evaluations may be enough to improve their lot later in life."