Responsa על קידושין 117:18

Q. A lent money to a Gentile at a definite rate of interest. B, then, approached the Gentile and said: "I shall let you have the money and charge you a smaller rate of interest than A. Take my money and pay him off."
A. It is doubtful whether B caused A a loss of money, since A may find another borrower for his money as soon as he receives it from the Gentile. Even if B definitely caused A a loss of money, he did so indirectly; therefore, B is under no obligation to A. However, B acted unethically and should be denounced and called rashah (wicked).
SOURCES: Cr. 59; Pr. 148; L. 375.

Q. A lent money to a Gentile at a definite rate of interest. B, then, approached the Gentile and said: "I shall let you have the money and charge you a smaller rate of interest than A. Take my money and pay him off."
A. It is doubtful whether B caused A a loss of money, since A may find another borrower for his money as soon as he receives it from the Gentile. Even if B definitely caused A a loss of money, he did so indirectly; therefore, B is under no obligation to A. However, B acted unethically and should be denounced and called rashah (wicked).
SOURCES: Cr. 59; Pr. 148; L. 375.

Q. B claims that A's moving into his (B's) settlement forced him (B) to move out and caused him a loss of 25 pounds. He demands that A make good his loss.
A. It is an everyday occurrence that Jews move into places, where no ban against new settlers exists, without asking permission from the established inhabitants of such places. Therefore, A is free from any obligation to B.
SOURCES: Pr. 382.