Phillippia Simmons reports that many of the studies which have investigated intra- and interracial crime seek to explain this through a theory of macrostructural opportunity which states that interracial violence is primarily a function of opportunity and access. According to this theory, intraracial crime rates remain relatively high due to the fact that much of the US remains residentially segregated. She notes that this theory predicts that, if residential areas were more racially integrated, intraracial crime would decrease and interracial crime would increase correspondingly. However, she also notes that not all researchers on the topic of intraracial crime agree with this result, with some pointing to other macrostructural factors, such as income and education, which may negate the effect of race on inter- and intraracial crime.