Boundaries of Generative AI Capabilities in Multi-tasking Environments

Last registered on July 06, 2026

Pre-Trial

Trial Information

General Information

Title
Boundaries of Generative AI Capabilities in Multi-tasking Environments
RCT ID
AEARCTR-0019108
Initial registration date
July 06, 2026

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
July 06, 2026, 9:40 AM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Locations

There is information in this trial unavailable to the public. Use the button below to request access.

Request Information

Primary Investigator

Affiliation
The University of Hong Kong

Other Primary Investigator(s)

PI Affiliation
The University of Hong Kong

Additional Trial Information

Status
On going
Start date
2026-03-28
End date
2026-10-31
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
Recent advancements in Generative AI (GenAI) have the potential to significantly enhance productivity and reshape workflows. A critical debate in exposed industries is whether GenAI should primarily be deployed as a labor-augmenting copilot, or as an autonomous agent that directly substitutes for human workers. In practice, jobs are typically designed as task bundles to balance specialization gains against coordination costs. Therefore, evaluating GenAI as an autonomous worker requires assessing not only its performance on isolated tasks, but also its ability to handle a multi-task bundle. To study this topic, we collaborate with a leading customer service company. Customer service is a typical multi-task job, comprising a bundle of tasks ranging from product consultation to personalized recommendation. These tasks differ fundamentally in their nature: some are standardized and require strict factual accuracy, while others are creative and require strategic persuasion to close the sale. To systemically evaluate GenAI’s performance in isolated tasks and task bundling relative to human workers, we will run three randomized controlled experiments (RCTs) that vary the degree of task bundling while holding other settings constant. Through these investigations, this study aims to inform the optimal design of human-AI workflows, providing micro-foundations for understanding the boundaries of autonomous agents versus augmenting copilots in complex work environments.
External Link(s)

Registration Citation

Citation
Wu, Yanhui and Zhenyu Zhu. 2026. "Boundaries of Generative AI Capabilities in Multi-tasking Environments." AEA RCT Registry. July 06. https://doi.org/10.1257/rct.19108-1.0
Experimental Details

Interventions

Intervention(s)
We will run three experiments varying in the task composition. In each experiment, we generate a set of scenario cards, each specifying the consumer demands embedded in a complete inquiry. The construction and assignment protocols are detailed in the next section. These cards are assigned to “consumers” (played by hired students) and service agents (GenAI or humans) following a fixed algorithm. Throughout the study, the GenAI agent serves as the treatment group, while human workers serve as the control benchmark.
Intervention Start Date
2026-03-28
Intervention End Date
2026-10-31

Primary Outcomes

Primary Outcomes (end points)
The key outcome is the agent performance in customer service.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
Customer service agents are divided into two groups: human agents and the GenAI agent. Each student is assigned 30 scenario cards, allocated evenly across treatment arms: 15 cards are designated for interactions with human agents, and 15 for the GenAI agent. We employed the greedy assignment algorithm to ensure that
• student characteristics are balanced across tasks;
• student characteristics are balanced between human and GenAI agents;
• task distribution is balanced between human and GenAI agents.

All human agents are required to participate in the experiment. Both human and GenAI agents serve students on a strictly one-on-one basis (i.e., no concurrent sessions). We maintain a constant active roster of three human agents and one GenAI agent account throughout the experiment. The daily sequence of interactions between students and agents (human vs. GenAI) is randomized to eliminate potential order effects. Agent identities are concealed to ensure a blinded design, meaning students cannot distinguish whether they are conversing with a human or the GenAI agent.
Experimental Design Details
Not available
Randomization Method
Customer service agents are divided into two groups: human agents and the GenAI agent. Each student is assigned 30 scenario cards, allocated evenly across treatment arms: 15 cards are designated for interactions with human agents, and 15 for the GenAI agent. We employed the greedy assignment algorithm to ensure that
• student characteristics are balanced across tasks;
• student characteristics are balanced between human and GenAI agents;
• task distribution is balanced between human and GenAI agents.
Randomization Unit
Randomization is conducted at the individual level.
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
Our experiment does not need to cluster the treatment.
Sample size: planned number of observations
1228
Sample size (or number of clusters) by treatment arms
574 inquiries are assigned to human agents, and 654 inquiries are assigned to AI agents.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials

There is information in this trial unavailable to the public. Use the button below to request access.

Request Information
IRB

Institutional Review Boards (IRBs)

IRB Name
Human Research Ethics Committee, HKU
IRB Approval Date
2026-02-23
IRB Approval Number
EA260130