There can be economic ones; art tourism is recognised as one of the world's fastest growing markets, attracting visitors who might spend an extra night or two in a city, dine in local restaurants and buy from nearby shops.
Then there are the things we might not realise art can do, such as making a woman feel safer walking through a laneway. That's what happened when David Svensson's Eyelight Lane, a neon light installation, was erected in Fort Lane. Previously a dimly lit alley which deterred some from using it as a convenient shortcut to Britomart, it now feels safer because it's a good deal brighter and busier.
A vibrant work such as Reuben Paterson's Andale, Andale at the Remuera Rd entrance to Newmarket Train Station, with its glittering flowers, might not be to everyone's taste but it can certainly lift one's mood on an otherwise bad day.
Public art helps us create identities that are distinct and unique to our part of the world, to celebrate our heritage and make our spaces more culturally vibrant. Think about great civilisations – they are remembered, in large part, for their art and culture.
Look at the outpouring of grief when Paris' Notre Dame came close to being razed to the ground, and the thanks given that many of the art and cultural treasures were saved. Equally remember the shock and tears shed for Afghanistan's Buddhas of Bamiyan, once the world's largest standing Buddhas, blown apart by the Taliban.
It shows us that public art matters; it's not to say we shouldn't debate, discuss and, yes, talk about the cost of it - after all, art is meant to challenge and provoke – but it should be balanced by a more nuanced appreciation of what it's doing for all of us and how soulless, dour and grim our communities would be without it.
Artist Ronnie van Hout's Boy Walking is about a young person walking optimistically into the future. A local authority that invests in public art has a sense of hope and values creative human endeavour, individuality and innovation – the same qualities that may help solve our transport, water and housing woes.