New York Times columnist and Nobel Prize winning Princeton economist Paul Krugman is battling plagiarism charges after a distinguished UCLA professor of economics leveled the accusation against him on his blog.

In an open letter to Paul Krugman, UCLA economics professor Roger Farmer alleges that Krugman stole his ideas and repackaged them in his New York Times columns.

“Perhaps you have read some of my recent work: Perhaps not. I infer that you may be aware of it since your columns often select themes that closely mirror my writings, usually a day or two after they are circulated. Perhaps that is due to the coincidence fairy,” writes Farmer.

Farmer says his accusations are not personal and that he likes Krugman’s works and shares many of his Keynesian economic views. However, Krugman’s failure to cite the professor’s work was a “step too far,” writes Farmer.

The plagiarism charges were so serious that Krugman felt compelled to address them in a curiously worded New York Times blog posting.

“A somewhat belated response to Roger Farmer, who accused me of cribbing from his writings. The truth is sadder; I haven’t read any of his stuff,” Krugman begins.

Then, in the next sentence, Krugman appeared to contradict himself by conceding that he was, in fact, familiar with Farmer’s writings and had read them.

“I’ve tried, a couple of times, but found it very hard to penetrate and gave up.”

Krugman used the rest of his blog post to lecture Farmer on the finer points of economic writing.

“Neither I nor most economists are going to make the effort of puzzling through difficult writings unless we’re given some sort of proof of concept–a motivating example, a simple and effective summary, something to indicate that the effort will be worthwhile,” Krugman wrote. “Sorry, but I won’t commit to sitting through your two-hour movie if you can’t show me an interesting three-minute trailer.”

Krugman added: “What every economist, and for that matter every writer on any subject, needs to realize is that unless you are a powerful person and people are looking for clues about what you’ll do next, nobody has to read what you write–and lecturing them about what they’re missing doesn’t help.”

New York Times editors have not commented on whether any internal investigation into the plagiarism allegation is underway.