ECON 410 — Interactive Module A

Bathtub Model of Unemployment · Mankiw Ch. 7
Section 4 · Module A

Set the monthly job-separation rate s and job-finding rate f. Watch the steady-state u* and average duration of unemployment update live.

u* = s / (s + f)
0.020
0.30
u* (steady-state)
6.25%
Avg job duration (1/s)
50.0 mo
Avg unemp duration (1/f)
3.3 mo
Per-month flow share
1.9%
QUICK SCENARIOS
Concept check
U.S. monthly s ≈ 1.5–2.5%, f ≈ 25–40%. With s=2%, f=30%: u* ≈ 6%. To get to 4% (full employment): s must drop to ~1.5% AND f rise to ~35%. Both must improve — labor markets are two-sided.

Start the economy at u₀ and watch it converge to u*. The convergence speed depends on (s+f).

10.0%
0.020
0.30
Steady-state u*
6.25%
u after 6 months
7.16%
u after 24 months
6.26%
Half-life of gap
2.2 mo
Speed of adjustment
The unemployment gap (u − u*) decays exponentially at rate (s+f) per month. So if (s+f) = 0.32, the half-life is ln(2)/0.32 ≈ 2.2 months. After ~6 months, the economy is mostly back to steady state.

Apply a recession shock at month 0 and see how u responds over 36 months.

PICK A SHOCK
Pre-shock u
5.0%
Peak u
5.0%
Time to peak
0 mo
Time to recover (90%)
0 mo
Recession asymmetry
In real life, s rises sharply at recession onset (mass layoffs) AND f falls (firms stop hiring). u jumps quickly. Recovery is asymmetric — s normalizes faster than f, so u falls slowly. This is why "jobless recoveries" happen.