The common mistake by both those who seek to abolish rents, and those who say rent is always permissible … is the failure to clearly differentiate and define rent, versus rent seeking.
Rent vs Rent Seeking
- Rent is granting another person limited access (but not ownership) to something of value that you produced (or purchased from a producer of value, etc), in exchange for something (usually currency) in return.
- Rent seeking is granting limited access to something one did not produce, in exchange for something in return.
Rent-seeking involves some kind of monopolization of value, for which one did not produce (or acquire from a producer).
- Land is arguably not produced. One may produce the buildings, farms, roads, fences, landscaping, and other 'things' of value on land… but the land itself is not produced. If one were to acquire a large plot of land (through various means), contribute little value, and merely charge rent to farmers for use of that land - arguably the land "owner" is simply monopolizing the space & the farmer himself is the primary producer and owner of value on that land.
- Intangible 'Property': Intangible ownership (i.e. Intellectual Property) sometimes qualifies as rent-seeking. Producing a unique work of art, such as a song, software, invention, or painting - is the production of value that would have never otherwise existed. However, less-unique intangibles (combinations, ideas, discoveries, categorical concepts) may have been first-accessed by an individual, though the value produced is in the access to the idea, but not the idea itself (metaphorically, like building a road). Charging rents or restricting access to non-unique ideas arguably qualifies as rent seeking, especially if the discover does not continue to contribute value.
- Currency Currency as it exists today is entirely fiat, monopolized, and preferential treatment is given to banks and those well connected to government(s). The value represented by currencies is (arguably) not produced by those who posses the currency, but is instead monopolized and exploited by them.
Re: The Left?
While "the right" often makes the mistake of not giving rent-seeking enough consideration, "the left" answers to rent seeking are highly problematic. Many leftist approaches seek to abolish rents in all forms, and "redistribute" the value produced by others towards themselves.
The important half-truth contained within the discussion of rents is the concept of produced value, versus non-produced value. One may have a superior claim to value they genuinely produced, but preventing access to value that one did not produce (or charging rents for access) becomes far more questionable whether that person 'deserves' that value anymore than anyone else.
Whether or not rent-seeking is "unjust" is a slightly more complex matter, but understanding the concept of rent-seeking (versus merely renting) allows this subject to be more honestly and accurately addressed.