Proponents argue that "Proposition 37 gives us the right to know what is in the food we eat and feed to our families. It simply requires labeling of food produced using genetic engineering, so we can choose whether to buy those products or not. We have a right to know." Opponents argued that "Prop. 37 is a deceptive, deeply flawed food labeling scheme, full of special-interest exemptions and loopholes. Prop. 37 would: create new government bureaucracy costing taxpayers millions, authorize expensive shakedown lawsuits against farmers and small businesses, and increase family grocery bills by hundreds of dollars per year." Opponents said Proposition 37 labeling requirements would increase grocery costs by as much as $400 per year based on a study by Northbridge Environmental Consultants and the non-partisan California Legislative Analyst's Office fiscal impact study. Proponents on the other hand, said that some organic US food processors argued that the changes in labeling will have no effect on consumer costs because companies change their labeling all the time, as it is, and changing labels is a regular cost already built into the price consumers pay for products. “We, as with most manufacturers, are continually updating our packaging. It is a regular cost of doing business - a small one at that - and is already built into the price consumers pay for products,” said
Arran Stephens, president and founder of Nature's Path. Proponents believed that if the proposition is accepted in California, it would increase the likelihood that other states will also adopt the same rules. In turn, if enough states do decide to adopt GMO labeling laws, it is possible that the national government will become involved and take action. Opponents claimed Prop 37 backers real intent was to ban GMOs via labeling schemes removing consumer choices, citing claims by proponents like
Jeffrey M. Smith that labeling requirements in California would cause food companies to source only non-GMO foods to avoid having labels that consumers would perceive as warnings. During the campaign, both sides made allegations of campaign improprieties. ==Campaign donations==