The story is of a house-master ("landowner" is our translation but it's not quite right) who goes out to the marketplace to find workers for the vineyard. He hires a group at 6 a.m. ("the first hour") and goes back to hire more at 9 a.m., noon, and 3 p.m. To the first group he promises a denarius, the "usual daily wage," and to the subsequent groups he promises "what is right." Finally he goes back at the eleventh hour (5 p.m.) and hires the last of those without work, sending them in to the vineyard for the last hour of the workday. Then he instructs the manager to pay each worker the full day's wage, starting with those hired at 5 p.m. This causes some resentment in those who worked all day; even though they were paid exactly what they expected, they do not appreciate the latecomers getting paid the same.
My perspective on this parable shifted at a synod assembly (of all places) when a pastor led a Bible study on it, retelling it from the perspective of the laborers who couldn't get hired all day and had to wait to the point of giving up before getting a last chance at work. It's easy enough to identify with those hired first, who work longest--we often feel that we are in that position. And it's easy to identify with the last hired, in an unreal way, as we sometimes feel ourselves to have received grace by the skin of our teeth. But hearing the story from the standpoint of actual day labor, where your family's ability to eat in the days ahead is dependent on being hired, made me feel differently about it. It's not actually easy to be looking for work and not finding it. And as a society, we tend to value the lives and welfare of those who are not working at a lower level than those who are (unless the people not working are living on investment income, in which case we tend not to object).
The parable confronts us with a scenario in which the house-master has chosen to honor the daily need of the workers rather than the hours they worked. No one would have objected if he'd pro-rated the wage for those hired later. It would be, in our world as in his, a kind of shrewd dealing and good stewardship to keep a lower but still technically "fair" wage for them. But the master in the story accepts both the hit to his "bottom line" and the resentment of the people he hired first in order to give a living wage to everyone.
It's worth running through this story a few times, putting ourselves in different places. How would we feel if we were the first hired? Or those hired mid-day, or at the last hour? How would we look at this scene--imagining a marketplace that always seems to have unemployed men looking for work--if we were the house-master? How would we interpret the master's command if we were the manager, handing out pay at the end of the day? The power of a parable is not that it makes a single point with a story, but that it invites us into a scene that has many possible meanings. We learn about ourselves and the assumptions we make when we hear it. And in that learning, Jesus is trying to show us something of the Kingdom of God.