PIMCO’s Mohamed El-Erian says that all assets are trading at “very artificial” levels due to central bank policies. El-Erian tells Yahoo! Finance’s Daily Ticker that central banks’ flooding of the markets with liquidity is the reason why stocks are up significantly this year while Treasury rates have actually fallen. He says that the U.S. economy is healing slowly, and that companies are helping markets by giving cash back to shareholders. But he says the markets are front-running central banks’ liquidity deluge, and that the most recent rise in U.S. markets is a front-running of the Bank of Japan’s loosening policies. All of this is okay if genuine growth at some point begins to drive things, El-Erian says — but if it doesn’t we could be in for big declines in asset prices as the liquidity flood stops. He says investors need to monitor things closely, and also should look at areas of the markets that aren’t driven by loose central bank policies, including some emerging markets and areas of U.S. markets that liquidity doesn’t reach.