Productivity of AI use in software coding not equal among users

Generative AI is reshaping software development – and fast. A new study published in Science by an international research team shows that AI-assisted coding is spreading rapidly, though unevenly. AI usage is highest among less experienced programmers, but productivity gains go to seasoned developers.

The study found that, by the end of 2024, around one-third of all newly written software functions in the United States were being created with the support of AI systems.

“We analyzed more than 30 million Python contributions from roughly 160,000 developers on GitHub, the world’s largest collaborative programming platform,” says Simone Daniotti, lead author of the study and researcher at Utrecht University. GitHub records every step of coding – additions, edits, improvements – allowing researchers to track programming work across the globe in real time.

The team used a specially trained AI model to identify whether blocks of code were AI-generated, for instance via ChatGPT or GitHub Copilot.

Experienced developers benefit most

“The results show extremely rapid spread of AI use,” says Frank Neffke, co-author of the study. “In the U.S. alone, AI-assisted coding jumped from around 5% in 2022 to nearly 30% in the last quarter of 2024.” 
The study also shows that the use of generative AI increased programmers’ productivity by 3.6% by the end of 2024. “That may sound modest, but at the scale of the global software industry it represents a sizeable gain,” says Neffke.

Experience levels matter: less experienced programmers use generative AI in 37% of their code, compared to just 27% for experienced programmers. Despite this, the productivity gains the study documents are driven exclusively by experienced users. “Beginners hardly benefit at all,” says Daniotti. Generative AI therefore does not automatically level the playing field; it can widen existing gaps. 

AI use increases productivity more for experienced users than beginner coders. Source: Daniotti et al. 2026.

Looking ahead

Software development is undergoing profound transformation. AI is becoming central to digital infrastructure, boosting productivity and fostering innovation – but mainly for people who already have substantial work experience.

The question is not whether AI will be used by people, but how we can benefit from it without reinforcing inequalities. “When even a car has essentially become a software product, we need to understand the hurdles to AI adoption – at the company, regional, and national levels – as quickly as possible,” Neffke says.

Publication

Simone Daniotti, Johannes Wachs, Xiangnan Feng, and Frank Neffke, Who is using AI to code? Global diffusion and impact of Generative AI (2026), Science (doi: 10.1126/science.adz9311). 

Daniotti did his PhD at Complexity Science Hub in Vienna and now he works as a researcher at Utrecht University. This newly published study was part of his PhD research.

Read more about this research on the CSH website.