Revisions to GDP don’t often change the
overall picture of the health, or lack thereof,
of the economy.
Despite cutbacks to congressional funding of
data collection at the federal level in recent
years, the GDP data are a lot more accurate
than they used to be.
About every five years, the BEA does a
“comprehensive revision” to GDP, and at that
point, GDP for any specific quarter is just
about as final as it will get, as the BEA has
98% of the data it needs to calculate GDP.