changes to the crude supply/demand balance, geopolitical iss c the trend in an instant. for "nightly business rep i'm jackie de angeles. >> and one factor that has a big impact is production in saudi arabia. and while the u.s. has surpassed that cntry as the world's biggest producer of oil, soon the saudis will hold the top spot in another competition. hadley gamble takes us behind the scenes as developers race to build what's slated to be the world's tallest . ♪ >> reporter: just north of jetta on the red sea on the western edge of saudi arabia the world's tallest building is under construction. set to top 3,300 feet, kingdom tower will soar above the skyline, setting a new standard for the 21st century skyscraper. but building the tallest structure on the planet is just the first step. billionaire saudi businessman has bigger plans for the site pouring $20 billion into the project to develop a multiuse economic city just minutes from downtown a city he hopes will lure foreign investors and create the jobs that saudi arabia needs. how involved is the prince? this is hic