The Peterson Institute for International Economics held a full-day conference on "Labor Market Slack: Assessing and Addressing in Real Time," on September 24, 2014. Participants for panel 2, "Constructing estimates of slack: dimensions of the difficulties," included: Wendy Edelberg, Congressional Budget Office; Michael Horrigan, US Bureau of Labor Statistics; Andrew Levin, International Monetary Fund and Dartmouth College; and William Wascher, Federal Reserve Board. David Stockton, Peterson Institute for International Economics, chaired the session. For more information about this conference, visit: www.piie.com/events/event_detail.cfm?EventID=349