Not knowing the ethnicity or religion of the returnees and non-returners is a big limitation. What if most of the returned letters from the Middle Eastern name were returned by people of either middle eastern decent or belonged to the Muslim religion? If data like ethnicity and religion of the participate were known we may look at the result of this study in a different light. Another possible limitation would be the envelopes. The placement of the envelops could of cause returnees not to see them causing are non return rate to be inflated. Another limitation with the use of envelopes is that the envelopes are made from paper and paper is frail. There may have been envelopes that were destroyed either by weather, vehicles, or just simply by a person not seeing it and stepping on them. Also by using envelopes it requires people to mail them off themselves, so that brings the question how many of the non-returned envelopes were just due to a participant being lazy instead of being bias?
Future research on the topic of Middle Eastern and Muslim discrimination and bias should stray away from the lost letter method, as it is not an effective way to measure true discrimination and bias. The current study raises the question of how to come up with a more effective method to measure discrimination and bias. If a better method were found it would be beneficial due to being able to tell if discrimination