And here's another, in my view not especially tenuous comparison with equal marriage.
Some people are afraid that extended opening hours on a Sunday or the maximal version, a 24/7 society, will have deleterious and damaging effects on society somehow. That's a legitimate concern - nobody wants society to be damaged - but how realistic is it? Anti-equal marriage people argue that equal marriage somehow damages society in some nebulous, vague, wavy-handy way. The point is that this isn't an untried experiment; it isn't something you have to guess at; you don't have to sit in an armchair puffing away on your pipe, pondering it, wondering "What if ...?" The first country to make equal marriage law was the Netherlands. That was back in 2001. Others have followed suit in dribs and drabs, but they were the first. Fourteen years on I think Dutch society, certainly in terms of social cohesion, liberalism, tolerance and equality, is doing just fine.
Skip to Sunday trading. Here the argument is stronger, because Sunday trading here goes back to 1994. It was done in the usual half-arsed, spit-and-sealing-wax fudged way that the British so often (preferentially, it seems) do things, but be that as it may or may it be not as it may not be, we had the change in the law twenty-one years ago. Are we worse off now than any time up to 1994, and specifically for that reason? I can't see how. The opposite, I think. I think we're better off in certain respects for the reasons that Prof. D outlined in an earlier post: it offers greater flexibility for those who need it, which often means working folk and especially working folk with kids and otherwise busy lives.