There is an easy way to determine this, and that's exactly what has been mentioned in the quote I keep including. A living wage should allow an individual to afford a minimum of things such as education and entertainment. This of course also refers to workers on the bottom quartile who generally are the most at risk of poverty. When we say that an individual needs something we mean needs a minimum while also avoiding poverty. Consumerism, which is subjective, isn't included. Whether you need an extra week of holiday doesn't matter when what you need is defined as that which allows you to avoid poverty.