1) "If SIAF is traded on two different exchanges, then it seems like you'd need to buy shares on Sweden's exchange in order to benefit from the dual listing. Is this true?" No, if the price rises in Sweden it will do so also in the U.S.
2) "If the two exchanges work independently and hence generate different prices for the stock, what does this mean for those holding shares on the exchange that lists the stock at lower prices? If the price is different, investors will buy shares where prices are lowest and sell at the market where prices are highest. It's called arbitrage.
3) Since the Swedish exchange has on average done better, if it gets dual listed would it be advisable to sell, say, have one's existing shares and buy them back on the Swedish exchange? No, the price will be the same in US.
Shares in Sweden will be traded as ADRs (in Sweden it is called SDB Svenska DepåBevis) http://www.investopedia.com/terms/a/adr.asp If I remember correctly it costs about $ 250 to convert ordinary shares into ADRs and the same if you have the ADR and want to convert into ordinary shares. Your broker will arrange this.
Even if you Americans will never buy or sell in Sweden, I am totally convinced that you will benefit from a listing in Sweden. If the price rises in Sweden it will rise in the U.S. also. Otherwise, the Swedes will buy shares in the U.S. and then convert the ADR and sell in Sweden and make a sure profit.
You will have absolutely nothing to worry about if SIAF is dual listing. The prices will always remain more or less in sync. I'm still impressed how SIAF is holding up well during all the slaughter in the sector lately. Very nice.
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