The business cycle
Economies do not grow in straight lines. They oscillate around a long-run trend in recognizable phases: expansion, peak, contraction (recession), and trough — then the next expansion begins. This rhythm is the business cycle, and tracking where we are inside it is the entire point of a recession monitor.
It's not a metronome
Cycles have no fixed length: US expansions have lasted from 12 months (1981–82) to 128 months (2009–2020). What recurs is the *sequence* — credit tightens, leading indicators roll over, activity contracts, policy eases, recovery begins. The timing varies; the mechanics rhyme.
Why it matters here
Every signal on this site maps to a phase transition in the cycle: the yield curve and housing permits sense the approaching peak; claims and the Sahm rule confirm the contraction; spreads widening mark the credit stress that usually accompanies it.