ster ), ▁co - ed ited ▁ ▁the ▁left ist ▁journal ▁Kon tr ast , ▁and ▁was ▁editor - in - ch ief ▁of ▁the ▁intellectual ▁journal ▁Ny tt ▁Nor sk ▁T ids sk rift ▁from ▁ 1 9 8 4 ▁through ▁ 2 0 0 9 . ▁Among ▁his ▁significant ▁publications ▁are ▁the ▁books ▁Constitution al ism ▁and ▁dem ocracy ▁( co - ed ited ▁with ▁Jon ▁El ster ), ▁De ▁nas jon ale ▁strateg er ▁( ” National ▁strateg ists ” ), ▁R ett ens ▁ir oni ▁( ” The ▁Iron y ▁of ▁Law ” ) ▁and ▁Sport en :   en ▁id é histor isk ▁stud ie ▁( ” S ports ” ), ▁a ▁study ▁of ▁sports ▁from ▁a ▁cultural ▁historical ▁point ▁of ▁view . ▁ ▁S lag stad ▁has ▁been ▁a ▁member ▁of ▁the ▁Norwegian ▁Academy ▁for ▁Language ▁and ▁Liter ature ▁( 1 9 9 6 - ), ▁the ▁Norwegian ▁Academy ▁of ▁Science ▁and ▁Let ters ▁( 2 0 0 2 - ), ▁and ▁on ▁the ▁board ▁of ▁M orgen bl ad et ▁( 2 0 0 3 – 2 0 0 9 ) ▁and ▁The ▁Dan ish - N or weg ian ▁Foundation ▁( 1 9 9 8 - ). ▁He ▁was ▁one ▁of ▁the ▁found ers ▁of ▁the ▁Norwegian ▁Social ist ▁Left ▁Party ▁( est . ▁ 1 9 7 5 ), ▁in ▁which ▁he ▁through ▁the ▁ 1 9 7 0 s ▁also ▁held ▁several ▁leading ▁positions . ▁ ▁From ▁ 2 0 0 9 -