 Yet, Donald Davis believed that both the Heckscher–Ohlin and Ricardian models were still relevant in explaining intra-industry trade.He developed the Heckscher-Ohlin-Ricardo model, which showed that even with constant returns to scale that intra-industry trade could still occur under the traditional setting.The Heckscher-Ohlin-Ricardo model explained that countries of identical factor endowments would still trade due to differences in technology, as this would encourage specialisation and therefore trade, in exactly the same matter that was set out in the Ricardian model.