“…Reflecting the abovementioned reasons, this topic attracts many sociologists and demographers. In fact, many studies have investigated the patterns and levels of educational assortative marriage across countries ( Halpin & Chan, 2003 ; Hou & Myles, 2008 ; Smits & Park, 2009 ; Smits, Ultee, & Lammers, 1998 ; Torche, 2010 ; Ultee & Luijkx, 1990 ) as well as trends within them ( Birkelund & Heldal, 2003 ; Mare, 1991 ; Park & Smits, 2005 ; Raymo & Xie, 2000 ; Schwartz & Mare, 2005 ; Wang & Wong, 2017 ; Wong, 2003 ). Since these studies show mixed empirical evidence on changes in educational assortative marriage in different countries ( Blossfeld, 2009 ), as we review below, multiple hypotheses have been proposed to explain cross-cultural differences in trends in educational assortative marriage.…”