Government always changes the playing field. Congress will add new programs and delete others. Some groups will get tax benefits while others will see their taxes rise. Investments in energy will be popular during one President’s administration while another President will favor increasing defense expenditures. It is not only the impact of Congress and the President but that of the various executive departments and agency rules on everything from drugs to housing materials.
In this time of instant communications, anything occurring in one part of the world will immediately be transmitted around the globe. How people react to an event can certainly cause short term unrest in the marketplace. For example, the Gulf War in the Middle East had a direct impact on the price of oil in the U.S., and in most other countries around the world.
Today businesses are global and interconnected. Businesses cross borders when they manufacture goods, purchase supplies and raw materials, and sell their merchandise. They can also be affected by currency exchanges which might make purchasing the same product cheaper from another country. Also political unrest can affect businesses not just locally but globally.