“…Furthermore, TE estimates have often been related to some 'farm-specific characteristics' 2 or socioeconomic variables to explain the differences in TE (Galanopoulos et al, 2006;Gaspar et al, 2009;Heshmati et al, 1995;Oude Lansink and Reinhard, 2004;Rowland et al, 1998;Sharma et al, 1999;Tonsor and Featherstone, 2009). Other studies have examined the relationship between animal welfare compliance and TE in pig production (Czekaj et al, 2013) or with environmental TE, where environmental inputs or outputs are included in the analysis (Asmild and Hougaard, 2006;PiotLepetit and Vermersch, 1998;Yang et al, 2008). An analysis divided according to production types (i.e.…”