High oil prices are here to stay, and they're caused by surging demand and limited new supply, not Wall Street speculators. That's the message from Fatih Birol, chief economist at the International Energy Agency. "Speculators are only responding to what is going on in the markets," Birol said. "We don't see enough oil in the markets. The major driver is supply and demand." Birol said growth in worldwide oil demand is outstripping growth in new supplies by 1 million barrels a day per year. Much of that new demand is coming from China, which is adding 800,000 vehicles to its...