Dive Brief:

• There is little doubt that the minimum wage debate is extremely heated. The latest research to dive into the mix comes from the National Employment Law Project, which published a study last week that examines employment levels before and after 22 federal minimum wage increases between 1938-2009.

• NELP, a progressive organization in Washington, DC, reports that historically there is "no correlation between minimum wage increases and employment levels," according to the San Jose Business Journal.

• However, opinions being what they are, no one can say for sure what impact raising the minimum wage would have on low-income workers or the economy overall. There are those who say the NELP study is not indicative of anything scientific about the minimum wage.

Dive Insight:

The Business Journal reported that the study was carried out by the University of California at Berkeley's Institute for Research on Labor and Employment. The City of San Jose had hired the institute to carry out a study on the impacts of a city and countywide $15 minimum wage by 2019. During a presentation in April 2015, U.C. Berkeley Professor Michael Reich said he felt credible researchers had come to differing conclusions, and mentioned U.C. Irvine Professor David Neumark, according to the Business Journal.

Neumark co-authored a study in May 2014 that criticized the methodology of studies that found raising the minimum wage has no effect on employment levels. Another 2014 paper co-authored by Neumark concludes: "While low wages contribute to the dire economic straits of many poor and low-income families, the argument that a higher minimum wage is an effective way to improve their economic circumstances is not supported by the evidence."

The debate will go on, and assertions in one direction or the other other will only be proven when the minimum wage laws begin to take effect.