It turns out that the num­ber of patents in a given tech­no­log­i­cal field is only weakly cor­re­lated with its rate of im­prove­ment. A far bet­ter pre­dic­tor is a mea­sure of how a patented tech­nol­ogy bor­rows from seem­ingly un­re­lated tech­nolo­gies. In­no­va­tion, it turns out, can come from any­where, and break­throughs are dri­ven by the in­cor­po­ra­tion of tech­nolo­gies into one an­other