Jacob Viner originally envisioned a situation where, in the demand/supply graph of a trade-diverting customs union, the demand curve was vertical and all supply curves (including the supply curve of domestic producers) were horizontal. Other things equal, would the formation of a customs union with many members be more likely or less likely to improve welfare for a given member country than the formation of a customs union with only a few members? Why or why not? Other things equal, would the formation of a customs union be more likely or less likely to enhance welfare for a given member country if that country had very high preunion tariffs than if it had very low preunion tariffs? Why or why not?