True/False with explanation

1. According to the Melitz model, exporting firms have higher sales on their domestic market than firms that only serve the domestic market.
2. According to the Melitz model, if Brexit raises barriers to trade between the UK and the EU then it will lead to a decline in the average productivity of British manufacturing.
3. If the costs of building factories abroad fall, we should see more horizontal FDI and fewer exports, other things being equal.