The entry on Urury in the Catholic Encyclopedia is quite long and pretty interesting. I suggest that people would do well to read it in its entirety, but several passages stood out to me. After covering some debate over interpretting scripture the entry noted:
“Nevertheless, the 12th canon of the First Council of Carthage (345) and the 36th canon of the Council of Aix (789) have declared it to be reprehensible even for laymen to make money by lending at interest. The canonical laws of the Middle Ages absolutely forbade the practice. This prohibition is contained in the Decree of Gratian, q. 3, C. IV, at the beginning, and c. 4, q. 4, C. IV; and in 1. 5, t. 19 of the Decretals, for example in chapters 2, 5, 7, 9, 10, and 13. These chapters order the profit so obtained to be restored; and Alexander III (c. 4, “Super eo”, eodem) declares that he has no power to dispense from the obligation. Chapters 1, 2, and 6, eodem, condemns the strategems to which even clerics resorted to evade the law of the general councils, and the Third of the Lateran (1179) and the Second of Lyons (1274) condemn usurers. In the Council of Vienne (1311) it was declared that if any person obstinately maintained that there was no sin in the practice of demanding interest, he should be punished as a heretic (see c. “Ex gravi”, unic. Clem., “De usuris”, V, 5).”
So, yes, it remains a moral sin. And, regarding its importance, the entry closes with this paragraph:
“Lending money at interest gives us the opportunity to exploit the passions or necessities of other men by compelling them to submit to ruinous conditions; men are robbed and left destitute under the pretext of charity. Such is the usury against which the Fathers of the Church have always protested, and which is universally condemned at the present day. Dr. Funk defined it as the abuse of a certain superiority at the expense of another man’s necessity; but in this description he points to the opportunity and the means which enable a man to commit the sin of usury, rather than the formal malice of the sin itself. It is in itself unjust extortion, or robbery. The sin is frequently committed. In some countries are found the exaction of interest at 30, 50, 100 percent and more. The evil is so great in India that we might expect legal provisions to fight against such ruinous abuse. The exorbitant charges of pawnbrokers for money lent on pledge, and, in some instances, of persons selling goods to be paid for by installments, are also instances of usury disguised under another name. As a remedy for the evil, respectable associations for mutual lending have been instituted, such as the banks known by the name of their founder, Raiffeisen, and help has been sought from legislators; but there is no general agreement as to the form which legislation on this subject should take.”
Which gets to the heart of the matter. It is the grave exploitation of the desperation of other human beings. Since we know that financial desperation leads to desperate acts (ex. financial desperation is a frequently reported causal factor in abortions) I would argue that the reasoning extended in then Cardinal Ratzinberger’s Doctrinal Note regarding the obligations of Catholics in public service and now Pope Benedict XVI’s SACRAMENTUM CARITATIS would apply. That is, I would take the controversal stance that Catholic politicians who voted for the bankruptcy bill in 2005, particularly those who voted to defeat amendments concerning exploitive and predatory lending practices, could reasonably be denied communion because of the public nature of their sin.
Best Regards