Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
•Added costs for non-GM ingredients and changes in demand for non-GM foods determine non-GM price premiums.•Non-GM price premiums were stable over the 8 year period of analysis.•US Consumers have been paying price premiums of 10–62% for the non-GM products analyzed.•The cost of mandatory labeling of GM foods depends on manufacturer decisions.•If food manufacturers reformulate with non-GM ingredients, costs to consumers could be substantial.