Causal Properties of Free String Field Theory

dσ(δX(σ)) < 0. Of more direct physical interest is the commutator of finite mass fields, obtained by smearing the string fields with appropriate wave functions. This is shown to vanish at spacelike separations, reproducing the usual point particle field theory result. The implications of this for the information spreading mechanism proposed by Susskind to solve the black hole information problem are discussed. Finally, it is verified that the above conclusions also hold for the superstring.