Thornton, Arland. 2009. "Framework for Interpreting Long-Term Trends in Values and Beliefs Concerning Single-Parent Families." Journal of Marriage and Family, 71(2): 230-234.
One of the most important trends of the last half of the 20th century was the dramatic rise in single parent families through increases in divorce and nonmarital childbearing. There were also shifts during this period in values and beliefs about divorce and childbearing. Single parenthood was also increasing during the first part of the century, and it is likely that these behavioral changes were accompanied by changes in public opinion. Unfortunately, whereas comparable repeated surveys have permitted changes in values and beliefs to be documented for recent decades, such data resources, to my knowledge, do not exist for the first half of the 20th century. This has left an important gap in our understanding of long-term trends in values and beliefs.