Micro Economics, the Importance of the Individual in the Big Picture

My academic field, economics, is thought to date back to publication of The Wealth of Nations written by Adam Smith in 1776. It was a break-through from religion, though Adam Smith was a religious, because clergy in the Western world for a thousand years or so had preached all of one's life was a gift from God. Smith said, no, wealth of nations came from individuals producing more than they consume. If humans divide up the work that is there to be done and each individual becomes specialized and more productive then trades his output with another specialist both will have more. Add them together the nation has more. 

Smith basic idea of the individual was expanded to the individual firm by Alfred Marshal in 1890. The same principle applied, that a nation because better off when individuals and firms seek to gain for themselves. This dominated economics until the Great Depression and John Maynord Keynes. Keynes' idea was prosperity and the standard of living of the public could be managed with government spending or not spending. Later the interest rate and money supply managed by the Federal Reserve was added to the arsenal of weapons available to "raise all ships." These gave birth to Macroeconomics and it has served well. 

Macroeconomics, managing taxes, expenditures and interest provides a feeling of power and control. Microeconomics, the tiny world of Adam Smith, was not exciting. Where is the grand improvement of peoples' lives in that?   

Today, we can see the power Adam Smith's micro economy. Individual people, making decisions in their own interests, sometimes bulldozes macro efforts to control them. One of them is the birth rate.

Each woman's or couple's choices about having children, when considered across a society, determine the birth rate. Dictators and religious leaders have little to no impact or influence on these choices. Yet, the changes in an economy from the birth rate may be greater than tax/spend or interest rate management by government. Today, 2/3rds of the countries in the world have birth rates below the replacement rate. The impacts of this, though some years in the future, seem profound.

A smaller labor force, fewer people to care for the growing population of elderly and the impact on the planet will all be big issues. Maybe microeconomics will be a bigger part of Economics 101.