Formulas Flashcards
Sharpe Ratio
measures excess return per unit of risk
r_portfolio - r_free / sigma_portfolio
Roy’s safety first ratio
r_portfolio - r_target / sigma portfolio
Correlation and covariance
corr(a,b) = cov(a,b) / (sigma_a*sigmab)
Normal distribution, percentage:
68%, 90%, 95%, 99%
1 sigma, 1.65 sigma, 1.96 sigma, 2.58 sigma
Standard error
sigma_x = sigma / sqrt(n)
Confidence interval
x+- z * sigma/sqrt(n)
z = 1.645 for 90% conf int z = 1.96 for 95% conf int z = 2.58 for 99% conf int
Type I and Type II error
Type I: rejection of null hypothesis when it’s actually true
Type II: failure to reject null hypothesis when it’s actually false
Reversal patterns
Head and shoulders, double/triple top or bottom
Continuation patterns
Triangle, rectangles, pennants, flags
Own price elasticity
% quantity demand change / % price change
> 1, elastic
< 1, inelastic
Income elasticity, normal good, inferior good
% quantity demand change/ % income
positive, normal good
negative, inferior good (as income increase, demand decrease)
Cross price elasticity
% quantity demand change / % price of related good
positive, substitute (increase in relative good price increase own price, since people choose the substitute over the more expensive)
negative, complement
Sealed bid
Highest bid wins, pays amount bid, bids are unknown to other bidders
Vickery bid
(second price sealed bid)
Highest bid wins, pays second high bid price
Dutch bid
(descending price)
Price decline until all units can be sold, each bidder pays price bid
Modified dutch
Price declines until all units can be sold, each bidder pays last price (lowest)
Fiscal budget deficit, saving and trade balance equation
G - T = (S - I) - (X - M)
Fiscal budget deficit = Excess saving - trade balance
Frictional unemployment
Time lag in matching qualified workers with job openings
Structural unemployment
Unemployed workers do not have the skills to match newly created job
Cyclical unemployment
Economy producing at less than capacity during contraction phase of business cycle
Money multiplier
Money multiplier = 1 / Reserve requirement
Fiscal multiplier
Fiscal multiplier = 1 / (1 - MPC * (1-t))
MPC - Marginal propensity to consume
t = tax rate
Increase in aggregae demand = gov spending * fiscal multiplier.
Ex: Gov spending = $100, tax is 25%, 75 is received by other, MPC = 80%, thus additional spending by who receives gov spending = 75* 0.8 = 60.
Then this 60 is again spent at 60 0.750.8, etc..
Expansionary and contractionary monetary policy
If policy rate < neutral interest rate, is expansionary
If policy rate > neutral interest rate, is contractionary
Expansionary and contractionary fiscal policy
When budget deficit is increasing or surplus is decreasing, it is expansionary
When budget deficit is decreasing or surplus is increasing, it is contractionary