http://www.FT.com/ US billionaire investor Jim Rogers tells Michael Mackenzie, the FT's US markets editor, that the US faces a painful slowdown in 2013. He also suggests the top of the commodities boom has yet to be reached and that agriculture is the most interesting commodities sector. <br /><br />For more video content from the FT, visit the Financial Times video section at: http://www.ft.com/video