Why do booms historically continue for several years? The answer is that as the boom begins to peter out from an injection of credit expansion, the banks inject a further dose. In short, the only way to avert the onset of the depression is to continue inflating money and credit. For only continual doses of new money on the credit market will keep the boom going and the new stages profitable. Furthermore, only ever increasing doses can step up the boom, can lower interest rates further, and expand the production structure, for as the prices rise, more and more money will be needed to perform the same amount of work. Once the credit expansion stops, the market ratios are re-established, and the seemingly glorious new investments turn out to be malinvestments, built on a foundation of sand. It is clear that prolonging the boom by ever larger doses of credit expansion will have only one result: to make the inevitably ensuing depression longer and more grueling.
~ Murray Rothbard