Julia there are good technical arguments for a microchip process for each person to carry vital information.
But my feeling is that making every person instantly accessible by a government is just too much of a risk to individual freedom.
Just consider the range of left and right wing dictatorships or even "democratic" governments we have seen in our lifetime. I think the potential for abuse of power is too high. Consider the Patriot Acts in America and the opportunity to detain people without trial or charge on suspicion of terrorism. I just wouldn't trust any government with that sort of power.