Professor Paul Amato has done some of the best work on how divorce effects children. This report he examines two large data sets and found that while there is clear evidence of divorce having adverse effects on children, the results “revealed a substantial degree of variability in children’s outcomes following parental divorce, with some children declining, others improving, and most not changing at all. The estimated effects of divorce appeared to be strongest among children with the highest propensity to experience parental divorce.” (from abstract).
Amato, P. R., & Anthony, C. J. (2014). Estimating the effects of parental divorce and death with fixed effects models. Journal of Marriage and Family, 76(2), 370-386. doi:10.1111/jomf.12100