NEW YORK/SAN FRANCISCO (Reuters) – Once the Federal Reserve lifts interest rates from near zero, likely this week, the focus will turn to the other legacy of the crisis-era policies: the Fed’s swollen balance sheet. The prevailing view is that the U.S. central bank’s $4.5 trillion portfolio, vastly expanded by bond purchases aimed at stimulating the economy, will have to shrink once rates are on their way up, and the Fed will just need to decide how quickly.