Opportunity cost is the next best alternative forgone.
It is caused by the scarcity of the resources. However, people always desire a better life and their wants are infinite so we have to make choices to maximise the pursuit of self-interest. This is also known as the basic economic problem.
Now, I would like to comment on the article about opportunity cost by Paul Hoang.The article gives examples of opportunity cost of having children and time.
The opportunity costs of having children are mainly the time and money that the parents could have spent for their own sake.
These cause the demographic model to change. Developed countries tend to have falling birth rates beacuse the number of women who participate in work is increasing nowadays. This is the case chlidren are the opportunity cost to their careers. Another reason to the demographic change is that the costs which the parent need to spent on children. The example of the costs are the compulsory education including kindergarden, primary and secondary, tuition fees and the tertiary education such as university, moreover, of course the additional living expenses. Those factors all contribute to the declining birthrate. This graph shows the demographic change of Japan.
The opportunity cost of time
"The phrase 'Time is money' is of absolute relevance in the business world" In other words, wasting your time causes losing of money. For example, your interest rate increases as you lend money to the banker longer. This means you cannot have your money on your hand and spend it while lending the deposits to the bank but the interest rate goes up instead.Therefore the opportunity cost of lending the deposits is the length of time and the opportunity cost of keeping from bank is the interest that you could have got.
I agree with both two ideas of the opportunity cost of having children and time because time is scarce so if you spend most of your time on your children, you wouldn't have your own time and therefore many women choose their carrers or their hobbies. Time is very imortant in business and everyday-life because no one wants to waste any of their time. Thus, saving your time often causes opportunity costs.
Here's a website explaining more about opportunity cost
http://www.econlib.org/library/Topics/HighSchool/OpportunityCost.html
Here's another article of opportunity cost of time
http://www.slate.com/articles/double_x/doublex/2013/02/time_is_money_opportunity_cost_can_help_you_figure_out_how_much_your_time.html
Aya