To defray the costs of training frontier models, some companies — such as OpenAI, Anthropic, and Google — keep them proprietary, or closed. That means users must pay to access the AI systems and to get responses from them.
Open models, such as those from Meta, DeepSeek, and Mistral, make one or more model details public, like model weights, source code, training data, or architecture. That openness means that users can host and run models locally.
In a new research paper, Frank Nagle, a researcher at the MIT Initiative on the Digital Economy, and Daniel Yue of Georgia Tech looked at the market for AI models. They found:
Closed models are far more commonly used than open ones, accounting for nearly 80% of all AI tokens that are processed on OpenRouter, a widely used marketplace for AI models. That means open models account for only about 20% of AI tokens processed. (A token is a unit of input to or output from an AI model, roughly equivalent to one word in a prompt to an AI chatbot.)
But closed models cost significantly more to run — $1.86 per million tokens, on average, compared with 23 cents per million tokens for open models.
Open models are closing the gap in quality. Open models achieved about 90% of the performance of closed models when they were released, but they were usually able to close the gap within 13 weeks of a closed model’s initial release.
Given all of the above, the researchers found that optimal reallocation of demand from closed to open models could cut average overall spending by more than 70%, saving the global AI economy about $25 billion annually.
So why aren’t more users already using open models? The researchers pointed to valid concerns about the costs of switching to new models and reliability, regulatory, or security concerns that are easier to assuage with closed models. There are also misconceptions about inferior performance and a lack of data privacy when it comes to open models.
Nagle encouraged companies to periodically review their use of AI models the same way they reevaluate software and infrastructure investments, and to consider whether there’s a more cost-effective way to meet their needs.
“The difference between benchmarks is small enough that most organizations don’t need to be paying six times as much just to get that little bit of performance improvement,” Nagle said. “They need to think about how to use the right tool for the right job instead of defaulting to what’s popular.”