The Voice Of America (VOA) has been using its own version of simplified English since 1959 and their archives are available to the public. I could only find one economics-business related article quickly though: "Simple English: American Agriculture: Shrinking but More Productive" [Profile]
The most interesting recent economic-business article I could find on the whole VOA site was about China buying into African oil, but it doesn't say it was written in special English: "China Oil Giant Reaches Deal to Buy Major Stake in Nigerian Oil Field". [Profile]
Comparing the profiles of the two articles:
China oil, not simplified: (80,4,8,8) vs.
American agriculture, simplified: (64,4,8,24)
Clearly, the VOA special English article routinely uses a lot more simple vocabulary, but note that 80% is near the 77% of the Wikipedia article I profiled. A more detailed study is obviously needed both characterizing lexically and grammatically these different forms of simplified writing and maybe also some objective computer-based measurement of how quickly students can read and understand these different kinds of writing.