Why firms become multinational companies?

well I'm no expert but i would imagine that one reason is so that the company can spread risks. If the economy is slow or demand is dropping in one country, chances are it will be thriving in another! Another reason may be to compete with larger companies and maybe to receive economies of scale. The market for many products if becoming more and more global-especially with the internet- and so its a case of 'multinational to survive'. Another motive is the size of the market. There may be (lets say for arguments sake) 1 million out of 60 million in the UK who want your product, where as there are billions in the world and so your market size would increase and so would sale. Lastly, with so many foreign businesses selling in the market, much of the market is taken by cheaper, bigger brands and so businesses must finnd market else where to replace the lost bits! Hope that helps but Im only doing A level business so Im no expert!! :-)