arXiv subjects

Drew Johnston

Publications and source records attributed to Drew Johnston.

6 recordsLinked to original sources

arXiv2026

The Shift to Agentic AI: Evidence from Codex

We analyze usage data from OpenAI's Codex tool to present large-scale evidence of how agentic AI technology, which can take actions on a user's behalf, changes how people work. We use an automated, privacy-protecting pipeline to contrast usage across three populations: external personal-account users, external organizational-account users, and workers within OpenAI. We find that agentic AI usage is growing rapidly: the number of active users has grown more than fivefold in the first half of 2026, with the most rapid increase occurring outside the initial audience of software developers. Uptake is uneven: within OpenAI, Codex usage is nearly universal and has largely replaced business usage of ChatGPT. We document a similar shift to agentic tooling outside OpenAI, particularly within organizations, although external adoption remains lower and more uneven. In addition to headline usage figures, we observe measures of sophistication, and find that a growing number of users have used Codex to change their workflows substantially. More than 10% of users manage three or more concurrent Codex agents at some point each week and that 26.6% use skills, which allow users to share instructions for complex workflows. Alongside these changes in usage practices, request complexity has increased: since the start of the year, the share of individual Codex users who submit at least one request for a task estimated to require more than eight hours for an experienced human to complete has increased nearly tenfold. Concurrently, output has grown rapidly -- in June 2026, the median OpenAI employee in a legal role generated 13 times more monthly output tokens across Codex and ChatGPT than they did in November 2025, while the median researcher generated more than 50 times as many. We conclude by discussing the implications of these patterns for productivity, job reorganization, and workforce restructuring.

econ.GN↗

arXiv2025

Measuring Global Migration Flows using Online Data

Existing estimates of human migration are limited in their scope, reliability, and timeliness, prompting the United Nations and the Global Compact on Migration to call for improved data collection. Using privacy protected records from three billion Facebook users, we estimate country-to-country migration flows at monthly granularity for 181 countries, accounting for selection into Facebook usage. Our estimates closely match high-quality measures of migration where available but can be produced nearly worldwide and with less delay than alternative methods. We estimate that 39.1 million people migrated internationally in 2022 (0.63% of the population of the countries in our sample). Migration flows significantly changed during the COVID-19 pandemic, decreasing by 64% before rebounding in 2022 to a pace 24% above the pre-crisis rate. We also find that migration from Ukraine increased tenfold in the wake of the Russian invasion. To support research and policy interventions, we will release these estimates publicly through the Humanitarian Data Exchange.

cs.CY↗

arXiv2024

Synthetic Medical Imaging Generation with Generative Adversarial Networks For Plain Radiographs

In medical imaging, access to data is commonly limited due to patient privacy restrictions and the issue that it can be difficult to acquire enough data in the case of rare diseases.[1] The purpose of this investigation was to develop a reusable open-source synthetic image generation pipeline, the GAN Image Synthesis Tool (GIST), that is easy to use as well as easy to deploy. The pipeline helps to improve and standardize AI algorithms in the digital health space by generating high quality synthetic image data that is not linked to specific patients. Its image generation capabilities include the ability to generate imaging of pathologies or injuries with low incidence rates. This improvement of digital health AI algorithms could improve diagnostic accuracy, aid in patient care, decrease medicolegal claims, and ultimately decrease the overall cost of healthcare. The pipeline builds on existing Generative Adversarial Networks (GANs) algorithms, and preprocessing and evaluation steps were included for completeness. For this work, we focused on ensuring the pipeline supports radiography, with a focus on synthetic knee and elbow x-ray images. In designing the pipeline, we evaluated the performance of current GAN architectures, studying the performance on available x-ray data. We show that the pipeline is capable of generating high quality and clinically relevant images based on a lay person's evaluation and the Fréchet Inception Distance (FID) metric.

cs.CV↗

arXiv2022

Migration patterns, friendship networks, and the diaspora: the potential of Facebook Social Connectedness Index to anticipate displacement patterns induced by Russia invasion of Ukraine in the European Union

The conflict in Ukraine is causing large-scale displacement in Europe and in the World. Based on the United Nations High Commissioner for Refugees (UNHCR) estimates, more than 7 million people fled the country as of 5 September 2022. In this context, it is extremely important to anticipate where these people are moving so that national to local authorities can better manage challenges related to their reception and integration. This work shows how innovative data from social media can provide useful insights on conflict-induced migration flows. In particular, we explore the potential of Facebook's Social Connectedness Index (SCI) for predicting migration flows in the context of the war in Ukraine, building on previous research findings that the presence of a diaspora network is one of the major migration drivers. To do so, we first evaluate the relationship between the Ukrainian diaspora and the number of refugees from Ukraine registered for Temporary Protection or similar national schemes as a proxy of migratory flows into the EU. We find a very strong correlation between the two (Pearson's r=0.94, p<0.0001), which indicates that the diaspora is attracting the people fleeing the war, who tend to reach their compatriots, in particular in the countries where the Ukrainian immigration was more a recent phenomenon. Second, we compare Facebook's SCI with available official data on diaspora at regional level in Europe. Our results suggest that the index, along with other readily available covariates, is a strong predictor of the Ukrainian diaspora at regional scale. Finally, we discuss the potential of Facebook's SCI to provide timely and spatially detailed information on human diaspora for those countries where this information might be missing or outdated, and to complement official statistics for fast policy response during conflicts.

physics.soc-ph↗

arXiv2020

Online Appendix & Additional Results for The Determinants of Social Connectedness in Europe

In this online appendix we provide additional information and analyses to support "The Determinants of Social Connectedness in Europe." We include a number of case studies illustrating how language, history, and other factors have shaped European social networks. We also look at the effects of social connectedness. Our results provide empirical support for theoretical models that suggest social networks play an important role in individuals' travel decisions. We study variation in the degree of connectedness of regions to other European countries, finding a negative correlation between Euroscepticism and greater levels of international connection.

econ.GN↗

arXiv2020

Towards a Virtual Reality Home IoT Network Visualizer

We present an IoT home network visualizer that utilizes virtual reality (VR). This prototype demonstrates the potential that VR has to aid in the understanding of home IoT networks. This is particularly important due the increased number of household devices now connected to the Internet. This prototype is able to function in a standard display or a VR headset. A prototype was developed to aid in the understanding of home IoT networks for homeowners.

cs.HC↗