RE: Vertical vs. horizontal transmission (was: JASSS Critical

Aaron Lynch (
Sat, 01 May 1999 12:40:12 -0500

Message-Id: <>
Date: Sat, 01 May 1999 12:40:12 -0500
From: Aaron Lynch <>
Subject: RE: Vertical vs. horizontal transmission (was: JASSS Critical
In-Reply-To: <000b01be93f2$2b102680$72223fce@rb4010>

At 09:46 AM 5/1/99 -0700, you wrote:
>This is a fascinating area to explore. What's the difference between a
>"doubling rate" and a "time constant"?


I assume that you are asking this for the benefit of readers who may not
have had any calculus courses, and I am happy to explain.

A time constant is the time it takes for an exponential function to
increase or decrease by a factor of e, the number equal to 2.718... It's
really a lot like a doubling rate, except that the time interval is a
factor of 1/ln(2) or 1.44 longer. That is, it's the doubling interval times
1.44. Not a big deal. People who mess with differential equations have
their reasons for preferring the factor of e rate to the doubling rate, the
tripling rate, etc.

--Aaron Lynch

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