Finland
Timo Klaukka Ari-Pekka Sihvonen National Public Health Institute Dept. of Health & Functional Capacity Mannerheimintie 166 FIN-00300 Helsinki Finland Tel: + 358 9 4744 8793 / Fax: + 358 9 4744 8924 E-mail: ari-pekka.sihvonen@ktl.fi Tapani Valkonen University of Helsinki Population Research Unit Department of Sociology P.O.Box 18 00014 Helsinki Finland Tel: + 358 (9) 19 12 38 9 / Fax: + 358 (9) 19 12 39 6 e-mail: tapani.valkonen@helsinki.fi