Mr Davis said in June that the Government had "50, almost 60 sector analyses already done" on the impact of Brexit and in October said that work had been undertaken in "excruciating detail".
To produce assessments into certain Brexit outcomes could impact individual sectors "was not a sensible use of resources", Davis told committee chair Hilary Benn.
He said the government had produced a "sectoral analysis" of different industries but not a "forecast" of what would happen when the United Kingdom leaves the EU.
'There's no systematic impact assessment I'm aware of, ' Davis told the parliamentary committee.
British Foreign Secretary Boris Johnson says Brexit negotiations must not be held up by disputes over Irish borders and that the issue should be tackled in phase two of departure talks.
"The assessment of that effect is not as straightforward as people imagine".
"Sectoral analysis was used for a real reason, it's the analysis of what the sector looks like". I am not a fan of economic models as they have all been proven wrong.
As recently as six weeks ago, he claimed impact assessments existed in "excruciating detail" and shortly afterwards published a list of the sectors that the work covered. When you have a paradigm change as in 2008, all the models are wrong.
"Ministers must now urgently undertake these impact assessments and ensure people are given the facts".
"Similarly, what we are dealing with here in every outcome - whether it is a free trade agreement, whether it is a WTO outcome or whether it is something between that on the spectrum - it is a paradigm change".
Lib Dem committee member Wera Hobhouse accused Davis of "misleading Parliament" over the studies.
Saying that he was "late" for his next appointment, Conservative MP Jacob-Rees Mogg reminded the secretary of state that Commons Speaker John Bercow had told the House that "nothing was more important" than for Davis to provide evidence to the committee.
Impact assessments would begin "a little closer to the negotiating timetable", Davis told the committee.
One arrested, two sought after shooting near Graham-Kapowsin High School
Troyer said that officers are investigating a motive for the shooting, and that it may have been gang-related. Troyer said they believe the two victims were students of the high school, but the shooters were not.