I think the closure of pubs is less to do with the cost of alcohol, more to do with the huge change in drinkers and their approach to drinking.
In previous generations, the pub was the central social hub of a village or town. You could go in and be pretty sure to see someone you know for a chat. At weekends, couples and families would go and meet other couples and families for a few drinks and some company.
Modern young drinkers - who are the majority - drink in order to be drunk, not for the socail aspect of gathering together to enjoy a drink. Therefore, 'vertical' bars have replaced pubs - major breweries who own pubs discovered that people drink more if they stand and drink rather than sit and chat, so a lot of pubs stripped out their seating - ending the social aspect of drining.
Add to that the supermarkets' massive cuts in alcohol for consumption at home, and you have a soceity that has enough drinks at home to 'get started', and the continuing in a vertical bar to become utterly incapable.
yes this is a generalisation - but look around any town at the ratio of vertival bars to old-fashioned pubs and you can see my point is proven.
Taking a penny off a pint will make no difference to anyone except the headline writers who wil spin it which ever way they choose, and the Tories who are so deluded that they think this sop to the 'ordinary people' willl get them some votes at the next election.