(Elsewhere he states that "the intrinsic nature" of interest and not the "financial position of the parties" make loans charging interest invalid.) Taji al-Din and Monzer Kahf argues that charging interest on loans restricts the circulation of wealth to those who already have it, since lenders do not provide loans to those who are unable to repay them. This (he believes) is forbidden by the Quran and results in an increase the divide between the rich and poor. Chapra notes that since banks are primarily interested in collateral to secure loans rather than the profitability of what the borrower/entrepreneur is seeking capital for, banks will finance rich borrowers with collateral rather than small borrowers with good ideas. Abul A'la Maududi calls interest "the greatest instrument by ... which the capitalist tries to concentrate in his hands the economic resources of the community", proclaiming "there is hardly a country in the world in which money-lenders and banks are not sucking the blood of poor labouring classes, farmers and low-income groups". M.A. Khan replies that these difficulties would not be solved by Islamic banking, firstly because "no business firm will extend credit to a customer until it is satisfied with its credibility", and secondly because there is no evidence that Islamic banking institutions have been focusing on the potential profitability of the proposals of entrepreneurs seeking capital rather than collateral. Overall, Khan writes, there is simply "no significant and rigorously argued study, of either Muslim or non-Muslim countries, showing that interest is causing or contributing to inequalities of income and wealth." General economic harm Among the claims that interest plays a negative role in the economy include that it squeezes out productive investment, encourages speculation, creates credit bubbles, fuels inflation, instability, unemployment, depressions and imperialism. Umer Chapra writes that by providing "easy access to credit for unproductive purposes", interest "squeezes the availability of resources for need fulfilment", squelching job creation. Maududi states that productive investment is withheld when enterprise seeking investment cannot yield a profit equal to the "prevailing rate of interest". Mohammad Abdul Mannan writes that eliminating interest would follow the cooperative norm of the Quran, and stimulate job creation and economic vitality. M.A. Khan replies that the harm created by interest cannot be that severe as interest-based finance is "deeply entrenched" in the developed countries of the OECD, where per capita income is quite high and the percentage of poor