... transactions in both London and Paris, to compare the implicit cost of trading French shares on the Paris Bourse and on SEAQ International The bid-ask spread is a major component of the total cost of. .. Group, London School of Economics, London) De Jong, Frank, Theo Nijman and Ailsa Ridell, 1994, Price effects of trading and components of the bid-ask spread on the Paris Bourse, Discussion paper... Ailsa Roell, 1993, A comparison of the cost of trading French shares on the Paris Bourse and on SEAQ International, Discussion paper no 9329 (CentER, Tilburg) and Discussion paper no 169 (Financial