The first and most widely recognized study,[57] published by Mathematica Policy Research, Inc. in 1985, found that the NAP program increased household food expenditures for beneficiaries when compared to non-participating families, just as its predecessor did.[58] It also found that the program had the same relevant impact on increasing household food expenditures as the previous food stamp program,[58] however this has been contested by subsequent studies performed on the national food stamp program, which found that "stamp" or "coupon"-type benefits are more effective at increasing food expenditures than direct "cash" benefits.[59] The 1993 study, which also researched the impact on household expenditures, formed a completely different conclusion: that the average beneficiaries under the NAP program spent $5 less per week on food than non-participating families, considering if both would have the same amount of resources available.[60] Nevertheless, this conclusion has also been questioned by subsequent research, attributing this result on the author's determination of the population sample.[60]