Neural networks revealed both how hard Covid-19 has hit the Chinese economy, and hopeful signs that a renaissance may be underway.
What’s new: Researchers at WeBank, a Chinese financial institution, analyzed satellite imagery, GPS signals, and social media to get a multifaceted view of the pandemic’s impact.
What they found: The team compared data collected before, during, and after the peak of China’s containment efforts. It focused on three data sources:
- Satellite images: The researchers adapted SolarNet, an image recognition model that maps solar panels based on infrared satellite photos, to look for heat signatures from steel mills. Then they correlated the results with steel output. In late January, at the height of the outbreak, China’s steel production had dropped to 30 percent of capacity, they found. By February 9, it had recovered to 76 percent.
- GPS: Using a different model, the researchers analyzed anonymized GPS signals collected in 2019 from millions of phones to determine whether they belonged to commuters. They used the results to estimate economic activity. Then they analyzed signals surrounding the quarantines to assess the impact. Comparing the datasets, they found that the country’s economic activity had fallen to 20 percent of normal by February 9. A month later, however, it had rebounded to 72 percent. Extrapolating the findings, they predict that China’s economy will recover fully by March 26.
- Social media: The  researchers used natural language processing to scan social media posts to determine whether people were working from homes or offices. According to that analysis, the number of telecommuters ballooned by more than sixfold between January 1 and mid-March.
Behind the news: China dramatically cut its coronavirus transmission rate by imposing strict measures to limit social interaction including a quarantine of 50 million people in the province that includes Wuhan, the disease’s epicenter.
Why it matters: Before Covid-19 rocked China’s economy, J.P.  Morgan had estimated that the country’s GDP would grow nearly 6 percent by the end of 2020. Now the U.S. investment bank predicts a meager 1 percent growth. China’s isn’t the only economy in trouble: The bank’s analysts warn of a global recession.
We’re thinking: China’s economic revival would be great news for the rest of the world. But full recovery isn’t likely until its Western trading partners come back up to speed.