No, recessions are by definition “significant, widespread, prolonged” declines in economic activity [0]
[0] from https://www.investopedia.com/terms/r/recession.asp but the three dimensions are, with various terms, common (BLS and NBER use “duration, depth, and diffusion”, CD Howe Institute in Canada uses “pronounced, persistent, and pervasive decline in economic activity” [1].) The two-quarter-GDP-decline rule is a rule focussed on the prolonged/persistent/duration dimension, but which does not capture the other two dimensions.
> "decline in economic activity" is a decline in GDP.
No, GDP is one of many measures of activity in the economy.
Also, “significant, widespread, and prolonged” are important qualifiers, and quarterly GDP is relevant to at most two (significant and prolonged) of them.
> Nobody defines a recession as a decline in employment
Not employment alone, no. But income has long been recognized as part of the multidimensional set of indicators that determines recession.
The Congressional Research Service in a 2008 report wrote:
A recession is a significant decline in economic activity spread across the economy, lasting more than a few months, normally visible in real GDP, real income, employment, industrial production, and wholesale-retail sales. A recession begins just after the economy reaches a peak of activity and ends as the economy reaches its trough. Between trough and peak, the economy is in an expansion. Expansion is the normal state of the economy; most recessions are brief and they have been rare in recent decades.
This is the generally accepted view among economists of what constitutes an economic recession. There is also a commonly cited "rule of thumb" that is referred to in the press. That rule is that a recession is two consecutive quarterly declines in real gross domestic product (GDP). But this rule does not always apply.
In 1974, the BLS Commissioner provided this set of rules of thumb for the depth (“significant”), duration (“prolonged”), and diffusion (“widespread”) elements of recession; note that employment is a factor in two of the three elements, just like output (at the time, GDP had not yet replaced GNP as the preferred output measure):
In terms of duration—declines in real G.N.P. for 2 consecutive quarters; a decline in industrial production over a six‐month period.
In terms of depth—A 1.5 per cent decline in real G.N.P.; a 15 per cent decline nonagricultural employment; a two point rise in unemployment to a level of at least 6 per cent.
In terms of diffusion—A decline in nonagricultural employment in more than 75 per cent of industries, as measured over six‐month spans, for 6 months or longer.
No, recessions are by definition “significant, widespread, prolonged” declines in economic activity [0]
[0] from https://www.investopedia.com/terms/r/recession.asp but the three dimensions are, with various terms, common (BLS and NBER use “duration, depth, and diffusion”, CD Howe Institute in Canada uses “pronounced, persistent, and pervasive decline in economic activity” [1].) The two-quarter-GDP-decline rule is a rule focussed on the prolonged/persistent/duration dimension, but which does not capture the other two dimensions.
[1] https://www.cdhowe.org/council-reports/canada-entered-recess...