That's the question that journalists, pundits and Remain voters have been trying to answer since Ebbw Vale, a town in southern Wales, came out against staying in the EU last month.
Wales, a net beneficiary when it comes to EU funding, voted to leave in the June 23 referendum.
In the Ebbw Vale area, the unemployment level is twice as high as the national average (5%), immigration is relatively low and the fruits of EU investment is visible for all to see. But 62% of voters there backed the Leave campaign.
Head to the site of the town's old steelworks -- now a state-of-the art "learning zone" with a huge sports center -- and it becomes apparent where much of the funding has gone.
According to the local council, the area received $9.68 million (£7.3 million) from the EU between 2007 and 2013 to invest in education, not just for schools but also for additional education facilities and training.
The EU has pumped in $192 million (£145 million) since the steelworks closed in 2002 and brought an end to the local area's main source of income.
The town center boasts a brand new silver statue of a dragon -- the Welsh national symbol -- and shiny silver balls that line the main street.
Both were built with $5.9 million (£4.5 million) in EU funds for physical improvements to the town's center.
Then there is the $105 million (£79 million) in EU funds that supported development of a new divided highway between Tredegar and Brynmawr, which has opened up employment and business opportunities across the South Wales Valleys.
Add that to a new railway line and $16.2 million (£12.2 million) for upgrades and improvements in the town center.
And EU funds have helped create 1,100 jobs in the local area, according to the Welsh government.
Still, when asked why they voted for "Brexit," many locals pointed to sovereignty and border control.
Deb Phillips, who voted to leave, told CNN she was "sick of being told where the money's got to be spent," with the dragon in the town center the focus of her ire.
Alan Jones, who voted to remain, said the EU investment won't be replaced equally by the British government.
"It's a stupid thing to do because once you go, this money is gone," Jones said of the decision to leave the EU.