Sub-replacement fertility
Only a few countries have had , for the time being , sufficiently sustained sub-replacement fertility ( sometimes combined with other population factors like higher emigration than immigration ) to have population decline , such as Japan , Germany , Lithuania , and Ukraine . 
<triplet> emigration <subj> immigration <obj> opposite of <triplet> immigration <subj> emigration <obj> different from <triplet> population decline <subj> emigration <obj> has effect