Take, make, waste vs. make, use, recycle (in a cycle)

In some contexts, you may have enough / more than enough of a good but in other contexts you may not (oxygen in most places vs. on Everest)

price of related goods, income, number of consumers, future price expectations, taste & preferences

What to produce (Big Mac vs. Filet o Fish), how to produce (machines vs. labor), for whom to produce (only those who can pay)

Normative: value judgements, concerned with equity vs. equality vs. positive: empirical evidence, ceteris paribus, use of logic etc.

the quantities of a product that consumers are willing and able to buy at various prices, over a period of time, ceteris paribus.

Additional benefit you get from consuming additional quantities of a good; additional benefit decreases since your enjoyment decreases with quantity

Free goods are naturally abundant and the quantity available is sufficient to satisfy all human wants, therefore do not incur any opportunity costs.

consumer rationality (driven by self-interests), utility maximization, perfect information

Consumer surplus is the positive difference between the amount that a consumer is willing and able to pay for a good and the amount they actually pay.

Mandated choices, default choices, restricted choices

Perfectly inelastic = vertical demand curve, PED = 0, single quantity demanded