diff --git a/draft-ietf-quic-recovery.md b/draft-ietf-quic-recovery.md
index bde35e40ab..a3393a77ba 100644
--- a/draft-ietf-quic-recovery.md
+++ b/draft-ietf-quic-recovery.md
@@ -951,8 +951,15 @@ This duration allows a sender to send as many packets before establishing
 persistent congestion, including some in response to PTO expiration, as TCP does
 with Tail Loss Probes ({{RACK}}) and a Retransmission Timeout ({{?RFC5681}}).
 
-The RECOMMENDED value for kPersistentCongestionThreshold is 3, which is
-approximately equivalent to two TLPs before an RTO in TCP.
+Larger values of kPersistentCongestionThreshold cause the sender to become less
+responsive to persistent congestion in the network, which can result in
+aggressive sending into a congested network. Too small a value can result in a
+sender declaring persistent congestion unnecessarily, resulting in reduced
+throughput for the sender.
+
+The RECOMMENDED value for kPersistentCongestionThreshold is 3, which results in
+behavior that is approximately equivalent to a TCP sender declaring an RTO after
+two TLPs.
 
 This design does not use consecutive PTO events to establish persistent
 congestion, since application patterns impact PTO expirations. For example, a