as they are of the Ewells. Perhaps, it is because Mr. Radley is not a drunkard and a blowhard, and the reclusive Radleys bother no one.

As Scout explains, undoubtedly realizing her readers would have no idea what the term alludes to, it means doing nothing. It's a euphemism for saying that Mr. Radley, at least as far as the children know, didn't work for a living. The origin of the term is obscure. It's obviously a regional Southern phrase that alludes to cotton, an important cash crop in the South. Various web sites explain that it means that Mr. Radley—or anybody who didn't work—would have bought rather than labored to make their own cotton cloth. That would imply having the independent income to do such buying. It might also mean he said he spent his time speculating in the commodities (cotton) market, but really he did nothing, just as today we might say "he buys stock" or "he's working on his novel."

In any case, the important point is that it indicates the children can't "place" Mr. Radley easily in the social hierarchy of Maycomb. Without a known job, Mr. Radley has no fixed, identifiable place in the community.

Jem says that Mr. Radley “bought cotton” because he does nothing.

The Radleys are the mystery of the block.  They are very reclusive people, and rarely interact with others.  The children are fascinated with Boo Radley, who seems to be so reclusive he never leaves the house.

I never knew how old Mr. Radley made his living- Jem said he "bought cotton," a polite term for doing nothing… (ch 1)

Mr. Radley apparently just walks to town once a day to buy groceries and only stays out for a half an hour.  The mystery of the Radleys is too much for Scout and Jem.  They come up with a variety of stories about the family, especially Boo.

To Kill A Mockingbird reveals the effects of narrow-mindedness and intolerance in the extreme. As the narrator, Scout commences the story of the innocent Tom Robinson's trial and conviction for the rape of Mayella Ewell by tracing the Finch family history. It is significant that she notes how important social standing is in Maycomb County and how it is "a source of shame" that the Finch family cannot trace their family back any further than Simon Finch. Scout mentions that it has always been a family tradition for the Finch men to make their living from cotton (which was a major source of income in the southern states) but Atticus, Scout's father, studied law and his brother Jack studied medicine instead. This reinforces the fact that Atticus is not a typical Maycomb County resident; in the 1930s his sense of equality and fairness is unique and is Tom Robinson's only hope in a town where racial prejudice is the norm and hypocrisy goes unrecognized by most.

There is a reliance on tradition in Maycomb County and Scout discusses the predictable activities of most of the townspeople for whom there appears to be no motivation or desire to change. Therefore, in this "tired old town" those folks who do not conform are frowned upon and the Radley family has its own special reputation of housing the "malevolent phantom" (chapter 1) which results in unwanted and unmerited gossip about the Radley family, especially Boo. There is a false sense of community in Maycomb and anyone who does not participate in this conceited and insincere version of polite but bigoted society must expect and accept stinging and unfair criticism.  

The Radley family members have always "kept to themselves." The only interaction that takes place is when Mr Radley regularly goes to town to buy what are presumed to be groceries. However, Scout cannot confirm or deny this and the only thing Scout knows is that Jem tells her that Mr Radley "bought cotton" which term Scout tells the reader is "a polite term for doing nothing." From an economic perspective, the southern states had relied on cotton historically and so this term infers that Mr Radley has no source of income from employment and lives on welfare. 

If you think about the lifestyles of those who lived in the south during the time period in which the novel is set, it should be relatively easy to understand that someone who "bought cotton" did nothing for a living.  Those who literally did buy cotton for a living (to sell, etc.) would probably have lived pretty easy lives in the eyes of those who did physical work, such as picking cotton.  To those who were in the fields, it probably seemed that men who spent their days in offices, etc., really did nothing.

It simply means that he does nothing for a living.  He might have money coming in from an inheritance or something like that.  While he doesn't do anything for a living, this is quite different from some families in Maycomb, like the Ewells, who live off "the bounty of county," which would be well-fare.

This means simply that Mr Radley appears to have no job. Scout remembers Jem describing him in this way, going on to remark that it was 'a polite term for doing nothing' (Chapter 1). In this respect Mr Radley appears rather unusual, but then the whole Radley family does. They generally keep themselves to themselves, and in this way they provide an endless source of fascination and speculation for the children, especially the most mysterious member of the family - the younger son Arthur Radley, whom the children nickname 'Boo'. Scout, Jem and Dill imagine him to be some kind of bogeyman, never realising until the end of the story that he is actually a very kind, caring, if extremely shy man who looks out for them. Scout learns in the course of the story to discount her childish fears and come to a better unerstanding of Arthur, and other people in general.