Trading the August jobs report: What could affect the number, and how investors may respond

Some economists see one variable that hold back Friday's jobs report: The end of a humanitarian program for Haitians.

The federal government said in late July that Haitians no longer qualified for Temporary Protected Status, following a favorable Supreme Court decision in June.

For more than a decade, the program had allowed hundreds of thousands of immigrants from the beleaguered Caribbean nation to live and work in the U.S. as long as it was considered unsafe for them to return "A key downside risk to August payrolls is the expiration of TPS-related work authorization for Haitian nationals," EY-Parthenon economists Gregory Daco and Lydia Boussour wrote to clients ahead of the release.

The pair said it's hard to know how many workers could be affected, given the potential for some to have switched to other visa types. But they said there could be a short-term drag on overall employment that may be most acutely felt in labor-heavy service industries. Economists polled by Dow Jones anticipate nonfarm payrolls still grew by 53,000 in August.

The unemployment rate is slated to hold steady at 4.1%. The change in the work authorization program probably acted as a drag on the ADP private payrolls release , according to Bill Adams, chief U.S. economist at Fifth Third Commercial Bank. ADP said companies added 38,000 jobs in August, down from the prior month and under the consensus forecast of 47,000.

Friday's headline payrolls number could result in notable swings for the S & P 500 , according to JPMorgan's trading desk. Here are the different outcomes the team is watching, and how the benchmark stock index could move in reaction: Gain above 95,000, 10% likelihood: The S & P 500 drops between 0.5% and 1.25%.

Gain between 65,000 and 95,000, 25% likelihood: S & P 500 slides between 0.25% and 0.5% Gain between 35,000 and 65,000, 30% likelihood: S & P 500 could fall as much as 0.25% or rise as much as 0.5%. Gain between 5,000 and 35,000, 25% likelihood: S & P 500 rises 0.25% to 0.75% Fewer than 5,000 jobs added, 10% likelihood: S & P 500 could retreat as much as 0.25% or rise gain as much as 0.5%.