S&P Global Ratings pushed back against claims of bias in assessing the creditworthiness of African governments, saying all receive equal treatment.

“We don’t treat Africa or Latin America or Asia — we don’t treat anybody different,” Roberto Sifon-Arevalo, global head of sovereign ratings, said in an interview on Thursday. “Our criteria, our methodology, has been public for decades now and anybody can look at it.”

He spoke on the sidelines of an S&P event during the Group of 20 summit in Johannesburg, where allegations of ratings companies treating African nations unfairly have repeatedly come up, including at the Bloomberg Africa Business Summit earlier in the week.

Even at S&P’s conference, Sim Tshabalala, chief executive officer of Standard Bank Group, Africa’s biggest lender, repeated the argument of ratings bias.

Tshabalala, who also heads a business task force under South Africa’s G20 presidency dealing with finance and infrastructure, said studies have found regional governments might be rated four grades lower than what their macroeconomic indicators imply.

Sifon-Arevalo rejected that notion, saying people were trying to compare African sovereigns with other economies that were structurally completely different.

“Sometimes when I speak with people looking at Africa specifically, their benchmark is Europe or the United States,” he said. “I rarely hear benchmarking themselves with Southeast Asia or Latin America.”

Still, South Africa’s central bank governor, Lesetja Kganyago, at a monetary policy committee announcement on the same day, said there was a lack of transparency over forecasting models the ratings agencies use.

“The rating agencies tell us that their models are proprietary,” he said. “So it is difficult to take their models and interrogate them and say where is this thing going.”

S&P’s ratings criteria and methodology have been public for decades, and anyone can replicate ratings assessments using them, Sifon-Arevalo said. Still, there is human judgment involved.

“Look, we’re people, we are entitled to opinions,” he said. “And our opinion might not be the same as as others. We try to do our best.”