Doulton - Econ Flashcards
(141 cards)
Elasticity
= the percent change in the quantity demanded for a 1% change in the price
Ed < 1 = inelastic (an increase in price leads to a small decrease in quantity, such that the overall revenue will still increase
Ed = 1 = Unit elastic (am increase in price is perfectly off-set by a change in quantity such that revenue will not change)
Ed > 1 = Elastic demand (An increase in price leads to a large decrease in quantity such that the overall revenue will fall
Formula given on sheet
Cross - Price elasticity
measures the responsiveness of the quantity demanded for a good to a change in the price of another good
Forumla given on sheet
Complements
An increase in price of Y leads to a decrease in the quantity sold of X
ex: if the price of X-box games go up, the sale of X-box consoles will decrease
Substitues
An increase in price of Y leads to an increase in the quantity sold of X
Ex: if the price of X-boc consoles go up, the quantity of PS4s sold go up
Demand Forecasting: Linear Trend
the growth in sales can sometimes be modelled using a linear trend, where Q is the quantity demanded and T is the time period
Equation:
Q = bo + b1T + error
Demand Forecasting: Exponential Trend
the exponential trend/exponential growth model is
Q= Ae^(b1T)
Demand Estimation:
Linear Regression
A linear regression model, used to predict demand can use any number of independent variables to predict the quantity of a product sold. The most relevant is the price of the product, but prices of other products and advertising expenditure for the product
Interpreting co-efficients:
once coefficients are found, they can be interpreted as the change in Q for a $1 change in the value of the variable.
Constant Elasticity of Demand
Must Transform in ln(Qx).
Interpreting co-efficients:
An increase inPx 1% will decrease Qx by b%
Coefficients in Demand Functions
Can only be included in the model if they are statistically significant (meaning they are statistically different than 0, recall from stats class) - therefore the Pvalue must be less than 5%
Rsquared (goodness to fit)
R-squared measures the proportion of the variation in your dependent variable (Y) explained by your independent variables (X) or all linear regression model.
We select the model with the adjusted R-squared value closest to 1. (because it implies that the independent variables of our model perfectly predict our dependent variable.
Average production of labour
gives us the total output, per unit of labour
Formula given
Marginal product
the additional output produced from 1 additional unit of labour
Formula given
Short Run (Capital is fixed, Labour is variable)
Capital is fixed, Labour is variable.
In the short run, only labour can be adjusted, and the amount of capital must be accepted as fixed (therefor rearrange)
Long run
Both Labour and Capital are variable.
In the Long run, both labour and capital can be adjusted, we must solve for both
Isocost - show all the combinations of L and K which you can get for the same cost
Isoquant - shows all the combinations of L and K which gives the same level of Output (Q)
Long Run profit maximation
MPk = MPL
____ ____
r w
Marginal Rate of Technical Substitution
- the slope of the isoquant line
- shows how much of one input you can replace with the other (the tradeoff between the inputs) to maintain the same level of output
- if the MRTS is constant (no variables in the equation) the inputs are perfect substitutes, which means the isoqaunt is a straight line and the tradeoff between K and L is the same no matter what the production level or level of inputs
When the inputs are perfect complements the isoquant is L shaped and only one combination of L and K will work for each output level since there is no direct rate off
Equation:
MRTS = - MP l
______
MP k
Cost of Production:
Sunk costs
= the costs has already occurred and therefor should not be considered when making decisions
Cost of Production:
Opportunity cost
= The income/profit that you are giving up by not pursuing an alternative option
Different cost models:
Cubic model:
C(q) = a + Bq + yq2 + Sq3
Quadratic:
C(q) = a + Bq + yq2
Linear:
C(q) = a + Bq
Economies of Scale
MC < ATC
Diseconomies of Scale
MC > ATC
Industry Structures:
- Perfect competition
- Monopoly
- Monopolistic competition
- Oligopoly
- for all industry structures, profit maximization occurs when MR = MC
Perfect competition
Many firms, each firm sells a small amount of the total market output.
each firm produces the same product.
Perfect information and zero transaction costs.
Firms can enter and exit the market without barrier
No firm has market power
Each firm must set their price at the price of the other firms (otherwise they will loose all their market share)
The long run economic profits are zero
Perfectly competitive firms:
MR = P
therefore
P = MC
Short-term profits under perfect competition
A firm should exit the market (shit-down condition) if the average variable cost (MC) is > than the price of the market (P)
The firm should produce at the level where P=MC if the avg. variable cost of production is less than the market price (P)
break-down:
P>ATC = positive economic profits (new firms enter market)
P=ATC = zero economic profits (revenues cover total costs, including opp. costs, but new firms have no incentive to enter
PAve variable cost the form will produce in the short run, but in long run may exit)