Inequality exists. It is impossible to eliminate and it is a mistake to try. Different people have different abilities. Even when two people have the same abilities, one might have fewer obstacles than another, or one might try harder than the other.
If we want the best person for a job, the one with the best combination of ability, opportunity and tenacity, we pay them more, right? If one job is more important than another job, we pay them more, right? It’s logical.
But how much more?
If we pay nothing more, zero difference, everyone gets paid exactly the same, that is roughly equivalent to communism: “from each, according to their ability; to each according to their need”. That is the minimum amount of inequality. Everyone gets paid exactly the same amount regardless of their abilities or their effort or the importance of the task they perform. A problem with communism is there is no incentive to work hard. Lazy people are not punished. Hard-working people are not rewarded. It’s not a recipe for success.
What about the other extreme? What is the maximum difference? Just a few people get paid everything. If you are one of the lucky few, you might think: “Life is great! I’m swimming in money! Economics is rational and objective, so I must be worth all this money. That means I’m really important! In fact, I must be much more important than all those poor people.” Is that a recipe for success? What kind of incentives are left for everyone else? Who thinks that is a recipe for success?
The optimum must be somewhere in between. Considering where we are now, and what the two extremes look like, which one do you think we are closer to? Which direction do you think we should pursue to maximize the incentives to work hard at the jobs that the economy (and society) needs the most?
People have different levels of motivation regardless of income. Some of the best examples of this are teachers and healthcare workers, who often have highly skilled, highly difficult labor and relatively poor pay. Independent of the renumeration, people who have the motivation to work will work. If all jobs payed equally, much of the labor of society would still be completed, but instead of having a profit-motive to complete work that pays well people would be incentivized to take up labor which they find personally fulfilling and are therefore more invested in completing well. However, this does leave jobs like waste disposal and mining under fulfilled, so it has been suggested that such undesirable jobs receive greater renumeration. An alternative to unequal pay based on job popularity would be a system known as ParEcon (participatory economics) where the average social value of every laborer's contribution must be equal (necessitating that they perform tasks which are less desirable in order to balance their time spent performing preferred tasks). Under a system like this, payment equity would be possible.