Are Hawaii residents staying at home during the COVID-19 pandemic?

The University of Hawaii Economic Research Organization set out to answer this using cellular location data.

UH researchers Justin Tyndall and Joshua Hu found that mobility data from Safegraph, which is collected from apps that run in the background of smartphones, could measure the willingness of residents to stay home.

The answer? Not to the same extent as last March, when the pandemic started.

UHERO launched the mobility data dashboard in December, to help track these trends. The data culled from Safegraph remains anonymous, UHERO says, and represents a selective sample of the population. However, it only includes Hawaii residents and not tourists, and those who have location data activated on their smartphones.

Over the holidays and into the start of the new year, at least a third, or 30% to 40% of Oahu and Lanai residents were staying home all day most days of the week —which is at about the same level as in July — when there were just a handful of cases. On neighbor isles, roughly 20% to 30% were staying home.

By contrast, last March, the share of people staying at home all day peaked at 42%, and over 40% again in August, when cases rose again.

The levels have stayed about the same since the start of this year and through the end of this month.

“We were thinking of different ways we can analyze economic activity and human movement around the islands,” said Tyndall. “We were on the lookout for different data sets that would allow us to add value.”

While Oahu is currently in Tier 2 in the reopening framework, staying at home and avoiding crowded spaces is still recommended by health officials as a way to prevent the spread of COVID-19, particularly following the recent spikes that resulted from holiday gatherings.

Social gatherings of up to five are allowed, whether at a restaurant dining table or at parks, beaches and other social gatherings.

Tyndall said UHERO is in talks with the Hawaii Pandemic Applied Modeling Work Group (HiPAM) about how the dashboard could also potentially serve as a warning indicator.

The data can be broken down by zip code or census tract. It also tracks foot traffic for various categories, including retail stores, restaurants, hotels, schools, universities, gyms and hospitals.

The stay-at-home rate on Oahu, at about 30%, is slightly higher than for neighbor isles, which are at 20 to 30%. Since Christmas, there has been a slight rise above 30%.

On Oahu, where people are staying at home most varies by zip code. About a third of people are staying at home in some parts of Honolulu, as well as Kaneohe and Kapolei, but less so in Kailua, Waikiki and the North Shore.

The highest rates of staying home, at above 50%, during the past two weeks, were in Mililani and a slice of Honolulu encompassing downtown and Kakaako.

Surprisingly, Tyndall said there seemed to be no apparent correlation between the average income of a neighborhood and stay-at-home rates.

Using foot traffic data, researchers found that visitors to retail stores and restaurants in December and January at about 60% of what it was prior to March. Foot traffic at hotels, which is at 30% of what it was prior to March, got a boost between Dec. 20 and Jan. 3, but went back down in the first week of January.

The study was posted online as an UHERO blog intended to stimulate discussion and critical comment, but has not undergone formal academic peer review.

The data will be updated weekly, according to Tyndall, and may be integrated into future UHERO forecasts.