Congress is again discussing reparations for slavery. It's a complex and thorny issue

Updated 1421 GMT (2221 HKT) February 18, 2021

(CNN)Slavery reparations are back in the national spotlight.

A House Judiciary subcommittee held a hearing this week to discuss establishing a federal commission that would explore how the US government might compensate the descendants of enslaved Americans.
And though the White House press secretary declined to say whether President Joe Biden would sign legislation to develop reparations for slavery, she did say he supported a study on the matter.
Lawmakers have been advocating for a federal effort to study slavery reparations for more than 30 years now -- to no avail.
But since the widespread protests last year against racial injustice and the inequalities laid bare by the Covid-19 pandemic, the debate has taken on a new urgency.
"At the very root of the word reparation is the word repair," Dreisen Heath, researcher and advocate for Human Rights Watch who testified at Wednesday's hearing, told CNN. "And the necessary process of repair is the only way we get to actually achieving racial justice."
So, just how would reparations, focused specifically on slavery, work?

Why are we talking about reparations again?

The idea of giving Black people reparations for slavery dates back to right after the end of the Civil War (think 40 acres and a mule). But for decades, it was mostly an idea debated outside the mainstream of American political thought.
That changed when writer Ta-Nahisi Coates published his 2014 piece in The Atlantic, "The Case for Reparations." In the years since, political leaders and members of the public have begun to take the issue more seriously.
The most recent movement on the topic came this week, when the House Judiciary Subcommittee on the Constitution, Civil Rights and Civil Liberties heard testimony on a piece of legislation known as HR 40.
The bill proposes the creation of a federal commission to study reparations and recommend remedies for the harm caused by slavery and the discriminatory policies that followed abolition. That commission would also consider how the US would formally apologize for the institution of slavery.
HR 40 has been repeatedly introduced in Congress since 1989, though it has never passed.
"Now more than ever, the facts and circumstances facing our nation demonstrate the importance of HR 40 and the necessity of placing our nation on the path to reparative justice," Rep. Shelia Jackson Lee, the lead sponsor of the bill, said at the hearing.
Lawmakers heard testimony from several people who spoke about why reparations were necessary for the nation to heal from slavery. Witnesses and experts pointed to how the concept had been applied internationally, as Germany did for the Holocaust, and even at home, after the internment of Japanese Americans.
Crucially, the passage of HR 40 wouldn't actually result in payouts to the descendants of enslaved Americans.
Rather, it would establish a group of appointed leaders to make recommendations on what compensation and other remedies to provide and how to go about doing so.

How do you put a cash value on hundreds of years of forced servitude?

This may be the most contested part.