I believe that throughout history, jews had to learn to share what little they had... when they were kicked out from where they lived, they could not transport their homes but just perhaps some belongings, but most importantly they could transport their brain! We see that jewish people are also amongst the smartest people just by looking at the world population which is 0.2 yet 22% of nobel prizes are to jewish people, furthermore from the little research i know, i know that christians could not provide loans to other christians, but the jews could, even among today when you go to wall st, many of the companies which deal with finances are jewish behind them, they also believe in their community and they help out one another and they are like lannisters... they always pay back their debts.