We question the usefulness of focusing on sophisticated ecosystem or other models for assessing financial risks (Nature 469, 302–303; 2011 and Nature 469 351–355; 2011) when practical solutions are to hand.

The main bottleneck is more political than technical, driven by a US banking oligarchy that effectively controls the economy. (Europe's and China's banks have more complex interactions with the state.)

We agree that traditional economic models need to be enhanced with interdisciplinary system theory in the medium and long term. But known short-term solutions have demonstrated their value in previous successful policies, and we should relearn and expand some of the old economic wisdom about the specific role of banks.

Banks are important because they create credit in a fractional reserve system, and credit markets are crucial allocators of capital to entrepreneurs. However, this is not considered in macro-economic models used by central banks (indirect influence through interest rates aside). The Austrian school of economists and scholars in the 1930s correctly emphasized that too much credit, encouraged by artificially low interest rates set by the central banks, can lead to bubbles and unsustainable booms. This is what happened in the run-up to the current financial crisis.

One problem that is often overlooked is the misalignment of interests between credit creation by banks for profit maximization versus the amount of credit required by the economy. The Glass–Steagall Act of 1933 reconciled these interests by separating investment, commercial and retail banking and insurance. Most scholars attribute much of the economic stability after the Second World War to this legislation. Its repeal in 1999 was the culmination of a decade of deregulation justified by the 'great moderation' (http://go.nature.com/ehkgvv), which turned out to be just a consequence of the actuation of a perpetual money machine that promised unrealistic economic growth.

We need to stop being blinded by complexity so that policy-makers can develop effective responses to the financial crisis and academics can create a genuine science of out-of-equilibrium system economics.