Robberies are increasing at a faster rate in England and Wales than in any other major developed country, research seen by the BBC suggests.
A new report says the wide use of smartphones and cuts to police patrols are behind the rise.
It also found some 269,000 young people were involved in or at risk of violence last year.
The Home Office said it was funding a police recruitment drive and helping officers to use their powers.
The new report from criminal justice consultants Crest Advisory examined robbery trends across Western nations – including Germany, Australia and France.
From 2010 to 2014, offences were on the decline almost everywhere.
Since then, however, there have been small increases in five countries – and a 33% rise in England and Wales, which researchers said was “significant” because robbery acted as an “entry point” for violent crime.
Harvey Redgrave, managing director of Crest Advisory, said: “It acts as a bit of a gateway offence into more serious violence, whether that’s because young people are being asked to carry out robberies as an initiation into gangs [or] whether it’s because they’re paying off debts.”
The report suggests the increase may be connected to the availability of smartphones, with eight in 10 people in the UK using them, higher than any other country.
It also cites pressures on policing, after 21,000 officer posts were cut between 2010 and 2018, pointing out that only 7% of robbery cases result in a suspect being charged compared with 21% four years ago.
“The opportunity to commit robberies may be greater here than in other countries,” said Mr Redgrave.
“Criminals respond to incentives and if they feel they’re not being effectively policed – often these are opportunistic crimes – we’re likely to see an increase in these types of offences.”
The Home Office suggested that changes in the way forces log robberies were partly responsible for the rise.
“We are pleased with improvements in police recording, which have contributed to reported increases in robbery offences,” said a spokesperson.
The spokesperson added: “We are giving police the tools they need to keep families, communities and our country safe, including recruiting 20,000 new police officers and making it easier for them to use stop-and-search powers.”
The report also analysed how many 10 to 17-year-olds experienced violence in England and Wales last year, producing an estimate of between 145,000 to 269,000, which is 5% of the under-18 population.