In a major study on Covid-19, researchers have revealed that physical distancing policies had little effect on lower-income people still needing to leave their homes to go to work.

"If lower-income people were simply ignoring the trend towards physical distancing, we would have expected them to continue going to places like supermarkets, liquor stores, and parks at the same rates as before," said study author Jonathan Jay from Boston University in the US.

According to the study, published in the journal Nature Human Behaviour, their visits dropped at almost the same rates as the very highest-income group.

"This indicates that lower-income people were just as aware and motivated as higher-income people to protect themselves from Covid-19, but simply couldn't stay home as much because they needed to go to work," Jay said.

For the study, the research team used anonymized mobility data from smartphones in over 210,000 neighbourhoods across the country, each neighbourhood categorised by average income.

They were able to see whether people from these neighbourhoods stayed home, left home and appeared to be at work–staying at another location for at least three hours during typical working hours, or making multiple stops that looked like delivery work.

The researchers also tracked movement to 'points of interest': beer, wine and liquor stores, carryout restaurants, convenience stores, hospitals, parks and playground, places of worship, and supermarkets.

"While people in high-income neighbourhoods retreated to home offices, people in low-income neighbourhoods had to continue to go to work–and their friends, family, and neighbours had to do the same," said study author Jacob Bor.

"Living in a low-income neighbourhood is likely a key risk factor for Covid-19 infection," Bor added.

To analyse the role that policies played in these mobility patterns, the researcher used the Covid-19 US State Policy Database (CUSP).

They found that the huge drop in mobility early in March had little to do with state policy, following similar patterns in different states regardless of when their orders went into effect.

"That people living in low-income households are more likely to face exposure to Covid-19 at work increases the importance of complementary policies, such as mask requirements in indoor spaces, that protect essential workers from Covid-19," the study authors noted..