For air cargo in 2013, shippers should expect a relatively slow first quarter that gradually leads into a more active summer. Barring any macroeconomic collapses — the debt-ceiling negotiations have the potential to wreck even the most conservative predictions — volumes and yields will continue to increase toward the end of the year, with the closing months of 2013 showing good growth. It’s a tale of two years, said Neel Shah, president of JS Aviation Consulting and ch...