²Finally, our more compact neural response selection architecture is well aligned with the recent socially-aware initiatives on reducing costs and improving fairness and inclusion in NLP research and practice (Strubell et al., 2019; Mirzadeh et al., 2019; Schwartz et al., 2019). Cheaper training (pretraining the proposed dual-encoder model on the entire Reddit costs only 85 USD) and quicker development cycles offer new opportunities for more researchers and practitioners to tap into the construction of neural task-based dialog systems.