Microeconomic formulas/MCQ points Flashcards
How is YED calculated?
% change in QD /
% change in income
How is XED calculated?
% change in QD of A /
% change in Price of B
If XED negative, its complementary, if its positive, its a substitute
How is PED calculated?
% change in QD
divided by
% change in P
HINTSB
How is PES calculated?
% change in QS
divided by
% change in P
PSSST
How are total costs calculated?
TC = TFC + TVC
How are avg costs calculated?
As well as AFC and AVC?
AC = TC / Q
AFC = TFC / Q
AVC = TVC / Q
AC is also known as ATC.
How do you calculate labour productivity?
Output / Total no. of workers
How is MC calculated?
(marginal cost)
Change in TC / Change in Q
How is TR calculated?
TR = P x Q
How is average revenue calculated?
AR = TR / Q
How is MR calculated?
(marginal revenue)
Change in TR / Change in Q
How is profit calculated?
TR - TC
TR = TC is profit and TR > TC is supernormal profit.
How are concentration ratios calculated, (calculating n-firm things)? + idea behind it
(Oligopolies)
- e.g. 3 firms control 90% of market, with 40 firms controlling another 10% of the market.
For calculations…
3-firm concentration ratio = 90%: - if market worth £45m, and 3-firm concentration needs to be calculated…
- 3 biggest firms have revenues of £15m, £9m and £7m…
- 3 firm concentration ratio is 15+9+7 / 45 x 100 = 68.9%.
(check flashcard 15)
The formula for calculating concentration ratio…
- revenue of each firm / total market value x 100
(check flashcard 14)
How to calculate MRP…
MRP = MPP x MR
(marginal revenue product = marginal physical product x marginal revenue)
MR = price or avg revenue (AR)
Why does MPP lower at some point?
(On a table)
- Due to the law of diminishing returns.
A function of the market mechanism…
- Providing incentives for firms to provide goods to make a profit
When calculating elasticities…
- % NOT required on calculator
- Remember to CORRECTLY POSITION VALUES in correct spaces ON FORMULA
- If below 1, inelastic and if above 1, elastic
- When looking at final value, plus or minus sign is IRRELEVANT
YED answers/values…
For a normal good:
- If YED income elastic/ + value - Normal luxury good
- If YED income inelastic? ‘-‘ value -> Normal necessity good
For an inferior good:
- If YED +1, income elastic
- If YED -1, income inelastic
- If YED zero, perfectly income inelastic
Working out govt. tax revenue from supply curves on diagram…
(MCQs)
(Be mindful of units e.g. price or qty may be in thousands etc)
To work out govt. tax revenue…
- highest price - lowest price on diagram (Price at y-axis) OR correct axis value
- Then, multiply this by qty at s2 (qty at x-axis)
—–> (Highest price - lowest price) x qty s2
(Revenue = price x qty)
Working out tax per unit when the govt. imposes an indirect tax…
(MCQs)
- Difference between highest price and lowest price
A left shift in AD leads to…
(UK financial crisis0
- Negative output gap and cyclical unemployment
(With additional LRAS curve and SRAS curve)