Air purifiers and workplace productivity

Last registered on July 31, 2023

View Trial History

Pre-Trial

Trial Information

General Information

Title

Air purifiers and workplace productivity

RCT ID

AEARCTR-0010161

Initial registration date

October 13, 2022

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

October 17, 2022, 5:23 PM EDT

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

Last updated

July 31, 2023, 11:36 PM EDT

Last updated is the most recent time when changes to the trial's registration were published.

Locations

Country

India

Region

Haryana

Primary Investigator

Name

Sachet Bangia

Affiliation

Harvard University

Contact Primary Investigator

Other Primary Investigator(s)

Additional Trial Information

Status

On going

Start date

2022-09-20

End date

2023-09-30

Keywords

Environment & Energy, Firms & Productivity

Additional Keywords

JEL code(s)

Secondary IDs

Prior work

This trial does not extend or rely on any prior RCTs.

Abstract

Air quality conditions are alarmingly poor in many developing countries. Many parts of India face grave levels of air pollution with conditions ranging from unhealthy to hazardous on most days. Decreased worker productivity due to elevated concentration of particulate matter has been documented in several contexts. White-collar workers spend most of their day indoors, and air purifiers are effective at improving indoor air quality even in high pollution settings by removing around 90% of particulate matter.

I am partnering with a call center in Haryana, India to run an impact evaluation of air purifier use. Workers at the call center sit on two floors, and the treatment is randomized at the floor-day level with one treated and one control floor each day. The study aims to address the following questions: (1) What is the short term impact of reducing indoor particulate pollutants on worker health, cognition and productivity? (2) What is the heterogeneity in individual sensitivity to indoor pollution?

External Link(s)

Registration Citation

Citation

Bangia, Sachet. 2023. "Air purifiers and workplace productivity." AEA RCT Registry. July 31. https://doi.org/10.1257/rct.10161-1.3

Sponsors & Partners

Experimental Details

Interventions

Intervention(s)

Air purifiers with HEPA filters that are effective at reducing particulate pollution indoors even in settings with extremely high outdoor pollution.

Intervention Start Date

2022-10-13

Intervention End Date

2023-02-05

Primary Outcomes

Primary Outcomes (end points)

Worker productivity

Primary Outcomes (explanation)

Worker productivity is closely tracked by the firm and this data will be made available to the researcher for analysis. The specific metrics that are relevant depend on the type of worker. There are 4 lines of business included in the study and each has its own performance metrics. The metrics capture both the volume of the work done (eg. number of calls received or made, number of customer support tickets closed) and quality of the work (eg. customer satisfaction ratings, quality audit checks etc.). I will construct one or two productivity indices using these metrics.

Secondary Outcomes

Secondary Outcomes (end points)

(1) Worker physical health and cognition
(2) Indoor air quality

Secondary Outcomes (explanation)

Worker health variables include measures of physical health collected by surveyors (heart rate, blood pressure, blood oxygen, measures of lung functioning, 1-minute handheld ECG reading for Heart Rate Variability) and self-reported symptoms, self assessed mood, fatigue, and ability to concentrate. Cognitive functioning is measured through computer games that test for attention, memory and inhibitory control. These outcomes will be collected one to two times per week for each participant.

Air quality monitors will continuously track PM10 and PM2.5 on both floors of the call center. This will be used to establish the first stage effect of the intervention.

Experimental Design

Treatment assignment will occur at a floor-day level, with one treated and one control floor each day.

Experimental Design Details

On days that a floor is treated, the air purifiers installed on that floor will operate normally. On days that a floor is the control, the HEPA filters will be removed from all air purifiers on that floor so they will operate as "sham" air purifiers.

Randomization Method

Using randtreat in stata, stratified by week.

Randomization Unit

Floor-day

Was the treatment clustered?

Yes

Experiment Characteristics

Sample size: planned number of clusters

160 floor-days

Sample size: planned number of observations

Around 120 employees on the two floors observed for 80 days.

Sample size (or number of clusters) by treatment arms

80 floor-days in control, 80-floor days in treatment

Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Using data from the same time period in the previous year to simulate power suggests a MDES on productivity metrics between 0.15-0.2 SD units (depending on the inherent variability in the metric), when the productivity is aggregated at the daily level. Using variation in air quality during the work shift along with the productivity will yield even more power for metrics that can be analyzed at a lower level of aggregation than the full day.

Supporting Documents and Materials

IRB