First-quarter growth is likely "stronger than whatever the government is going to publish at the end of this month", Goldman Sachs chief economist Jan Hatzius told CNBC Friday.
Hatzius says that ISM data, used by Goldman's new Current Activity Indicator, are "consistent with significantly more growth than the GDP" data currently indicate.
Goldman's CAI looks beyond GDP to include labor and industrial production data, among others. "If you want to take a broad view of economic activity it does make sense to cast a net as wide as possible," Hatzius said.
But he stressed the CAI is just "one part of the arsenal we look at. I would never say there is one indicator that trumps everything else."
The economist believes the Federal Reserve will not raise interest rates this year or next year because the economy is still weak.
"We think it is going to take a long time before we see any significant change in monetary policy," he said. Removing food and energy from the equation, inflation "came in lower than expected, and ultimately that will be more important for the Fed when setting interest rates."