[Script Info] Title: [Events] Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,♪ [music] ♪ Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,- [Alex] In our first lecture\Non the elasticity of demand, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,we explain the intuitive meaning\Nof elasticity. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,It measures the responsiveness\Nof the quantity demanded Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,to a change in price. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,More responsive means more elastic. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,In this lecture, we're going\Nto show how to create Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,a numeric measure of elasticity. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,How to calculate with some data\Non prices and quantities, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,what the elasticity is over a range\Nof the demand curve. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So here's a more precise definition\Nof elasticity. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,The elasticity of demand\Nis the percentage change Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,in quantity demanded divided\Nby the percentage change in price. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So let's write it like this.\NWe have some notation here. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,The elasticity of demand is equal\Nto the percentage change in. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Delta is the symbol for change in,\Nso this is the percentage change Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,in the quantity demanded\Ndivided by the percentage change Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,in the price. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,That's the elasticity of demand.\NLet's give an example or two. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So, if the price of oil increases\Nby 10% and over a period Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,of several years the quantity\Ndemanded falls by 5%, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,then the long run elasticity\Nof demand for oil is what? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Well, elasticity\Nis the percentage change Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and the quantity demanded. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,That's -5% divided\Nby the percentage change Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,in the price. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,That's 10%. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So the elasticity of demand\Nis -5% divided by 10%, or -0.5. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Elasticities of demand\Nare always negative Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,because when price goes up,\Nthe quantity demanded goes down. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,When price goes down,\Nthe quantity demanded goes up. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So we often drop the negative sign\Nand write that the elasticity Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,of demand is 0.5. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Here's some more important notation. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,If the absolute value\Nof the elasticity of demand Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,is less than one,\Njust like the example Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,we just gave for oil, we say\Nthat the demand curve is inelastic. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Elasticity of demand less than one,\Nthe demand curve is inelastic. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,If the elasticity demand\Nis greater than one, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,we say the demand curve is elastic. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And if elasticity of demand\Nis equal to one, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,that is the knife point case,\Nthen the demand curve Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,is unit elastic. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,These terms are going to come back,\Nso just keep them in mind. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Inelastic: less than one.\NElastic: greater than one. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So we know that elasticity\Nis the percentage change Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,in quantity divided\Nby the percentage change in price, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,how do we calculate\Nthe percentage change in something? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,This is not so hard,\Nbut it could be a little bit tricky Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,for the following reason. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Let's suppose you're driving down\Nthe highway at 100 miles per hour. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,I don't recommend this,\Nbut let's just imagine Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,that you are. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,You're going 100 miles per hour,\Nand now you increase speed by 50%. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,How fast are you going?\N150 miles per hour, right? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Okay, so now you're going\N150 miles per hour. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Suppose you decrease speed by 50%.\NNow, how fast are you going? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,75 miles per hour, right? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So how is it that you can\Nincrease speed by 50% Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and then decrease by 50%\Nand not be back Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,to where you started? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Well the answer is,\Nis that intuitively, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,we have changed the base\Nby which we are calculating Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,the percentage change. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And we don't want to have\Nthis inconsistency Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,when we calculate elasticity. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,We want people to get\Nthe same elasticity Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,whether they're calculating\Nfrom the lower base Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,or from the higher base. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So, because of that, we're going\Nto use the Midpoint Formula. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So, the elasticity of demand,\Npercentage change in quantity Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,divided by the percentage\Nchange in price, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,that's the change in quantity\Ndivided by the average quantity Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,times 100. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,That will give us the percentage\Nchange divided by Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,the change in price\Ndivided by the average price. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Again, that times 100. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Notice, since we've actually got\N100 on top and 100 on the bottom, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,those 100s we can actually\Ncancel out. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Let's expand this\Njust a little bit more. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,The change in quantity.\NWhat is the change in quantity? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Well, let's suppose\Nwe have two quantities. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Let's call them after and before. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,It doesn't matter which one\Nwe call after or which one before. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So, we're going to then expand this\Nto the change in quantity. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,That's Q after minus Q before\Ndivided by the average, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Q after plus Q before,\Ndivided by two, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,divided by the change in price,\NP after minus P before, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,divided by the average price,\Nb after plus b before, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,divide by two. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So that's a little bit of a mouthful,\Nbut everything, I think, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,is fairly simple. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Just remember change in quantity\Ndivided by the average quantity Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and you should always be able\Nto calculate this. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Let's give an example. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Okay, here's an example\Nof a type of problem Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,you might see on a quiz\Nor a mid term. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,At the initial price of $10,\Nthe quantity demanded is 100. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,When the price rises to $20,\Nthe quantity demanded Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,falls to 90. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,What is the elasticity is, \Nwhat is the elasticity over Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,this range of the demand curve? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Well, we always want\Nto begin by writing down Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,what we know -- our formula. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,The elasticity of demand\Nis the percentage change Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,in quantity divided\Nby the percentage change in price. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Now, let's remember\Nto just expand that. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,That's Delta Q over the average Q\Nall divided by Delta P Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,over the average P. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Now, we just start\Nto fill things in. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So our quantity after, okay,\Nafter the change is 90. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Our quantity before that was 100. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So on the top,\Nthe percentage change Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,in quantity is 90 minus 100\Ndivided by 90 plus 100, over two. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,That is the average quantity. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And then on the bottom,\Nand the only trick here Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,is always write it\Nin the same order, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,so if you put the 90 here,\Nthen make sure you put the 20, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,the number the price\Nwhich is associated Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,with that quantity started off\Nthe same way. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So, always just keep it\Nin the same order. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So on the bottom, then,\Nwe have the quantity -- Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,the price after -- which is 20\Nminus the price before, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,which is 10, divided\Nby the average price. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And now, just, it's numerics. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,You plug in the numbers\Nand what you get is the elasticity Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,of demand is equal to -0.158,\Napproximately. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,We can always drop\Nthe negative sign Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,because these things,\Nelasticity of demands, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,are always negative. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So it's equal to 0.158. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So does this make the elasticity\Nof demand over this range Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,elastic or inelastic? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Inelastic, right? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,The elasticity of demand\Nwe've just calculated Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,is less than one,\Nso that makes this one inelastic. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,There you go. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,We need to cover one more\Nimportant point Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,about the elasticity of demand,\Nand that is its relationship Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,to total revenue. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So a firm's revenues\Nare very simply equal Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,to price times quantity sold. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Revenue is equal\Nto price times quantity. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Now, elasticity, it's all about\Nthe relationship Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,between price and quantity, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and so it's also going\Nto have implications for revenue. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Let's give some intuition\Nfor the relationship Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,between the elasticity\Nand total revenue. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So revenue is price times quantity. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Now suppose the price goes up\Nby a lot and then quantity demanded Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,goes down, just by a little bit. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,What then is going to be\Nthe responsive revenue? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Well, if price is going up\Nby a lot and quantity Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,is going down just by a little bit,\Nthen revenue Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,is also going to be going up. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Now, what kind of demand curve\Ndo we call that, when price goes up Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,by a lot and quantity falls \Nby just a little bit? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,We call that\Nan inelastic demand curve. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So, what this little thought\Nexperiment tells us Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,is that when you have\Nan inelastic demand curve, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,when price goes up\Nrevenue is also going to go up, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and of course, vice versa. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Let's take a look\Nat this with a graph. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So here's our initial demand curve,\Na very inelastic demand curve, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,at a price of $10, the quantity\Ndemanded is 100 units, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,so revenue is 1,000. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Notice that we can show revenue\Nin the graph Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,by price times quantity. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Now, just looking at the graph,\Nlook at what happens Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,when the price goes up to 20. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Well, the quantity goes down\Nby just a little bit, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,in this case to 90,\Nbut revenues go up to 1,800. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So you can just see,\Nby sketching the little graph, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,what happens to revenues\Nwhen price goes up Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,when you have\Nan inelastic demand curve. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And again, vice versa. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Let's take a look\Nabout what happens Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,when you have\Nan elastic demand curve. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So let's do the same kind\Nof little thought experiment, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,revenue is price times quantity. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Suppose price goes up\Nby a modest amount Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and quantity goes down\Nby a lot. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Well, if price is going up\Nby a little bit and quantity Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,is going down by a lot,\Nthen revenue must also be falling. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And what type of demand curve\Nis it when price goes up Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,by a little bit,\Nquantity falls by a lot? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,What type of demand curve is that? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,That's an elastic demand curve. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So, revenues fall as price rises\Nwith an elastic demand curve. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And again, let's show that. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,If you're ever confused\Nand you can't quite remember, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,just draw the graph. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,I can never remember, myself,\Nbut I always draw Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,these little graphs. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So, draw a really flatter,\Nelastic demand curve. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,In this case, at a price of $10,\Nthe quantity demanded is 250 units. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So revenues is 2,500. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And see what happens,\Nwhen price goes up, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,price goes up to $20,\Nquantity demanded falls to 50, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,so revenue falls to 1,000. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And again, you can just compare Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,the sizes of these\Nrevenue rectangles Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,to see which way\Nthe relationship goes. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And of course, this also implies,\Ngoing from $20, the price of $20 Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,to the price of $10,\Nrevenues increase. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So with an elastic demand curve,\Nwhen price goes down, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,revenues go up. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So here's a summary\Nof these relationships. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,When the elasticity of demand\Nis less than one, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,that's an inelastic demand curve\Nand price and revenue Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,move together. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,When one goes up,\Nthe other goes up. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,When one goes down,\Nthe other goes down. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,If the elasticity of demand \Nis greater than one, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,that's an elastic demand curve\Nand price and revenue move Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,in opposite directions. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And could you guess what happens\Nif the elasticity of demand Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,is equal to one --\Nif you have a unit elastic curve? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Well then, when the price changes,\Nrevenue stays the same. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Now, if you have to, again,\Nmemorize these, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,but it's really much better\Nto just sketch some graphs. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,I never remember them,\Nas I've said myself, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,I never remember\Nthese relationships, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,but I can always sketch\Nan inelastic graph Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and then with a few changes\Nin price, I can see Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,whether the revenue rectangles\Nare getting bigger or smaller Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and so I'll be able to recompute Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,all of these relationships\Npretty easily. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Here's a quick practice question. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,The elasticity of demand for eggs\Nhas been estimated to be 0.1. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,If egg producers raise their prices\Nby 10%, what will happen Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,to their total revenues? Increase?\NDecrease? Or it won't change? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Okay, how should we\Napproach this problem? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,If the elasticity of demand is 0.1,\Nwhat type of demand curve? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Inelastic demand. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Now, what's the relationship\Nbetween an inelastic demand curve? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,When price goes up,\Nwhat happens to revenue? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,If you're not sure, \Nif you don't remember, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,draw some graphs. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Draw an inelastic,\Ndraw an elastic, figure it out. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Okay, let's see. What happens?\NRevenue increases, right? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,If you have an inelastic\Ndemand curve and price goes up, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,revenue goes up as well. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Here's an application. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Why is the war on drugs\Nso hard to win? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Well, drugs are typically\Ngoing to have Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,a fairly inelastic demand curve. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,What that means\Nis that when enforcement actions Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,raise the price of drugs,\Nmake it more costly to get drugs, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,raising the price,\Nthat means the total revenue Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,for the drug dealers goes up. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So check out this graph. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Here is the price\Nwith no prohibition, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,here's our demand curve,\Nour inelastic demand curve. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,What prohibition does,\Nis it raises the cost Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,of supplying the good. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,But that raises the price,\Nwhich is what it's supposed to do, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and that does reduce\Nthe quantity demanded of the drug. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,But it also has the effect\Nof increasing seller revenues. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And seller revenues may be\Nwhere many of the problems Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,of drug prohibition come from. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,It's the seller revenues\Nwhich drive the violence, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,which drive the guns,\Nwhich make it look good Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,to be a drug dealer,\Nwhich encourage people Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,to become drug dealers,\Nand so forth. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So there's a real difficulty\Nwith prohibition, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,with prohibiting a good,\Nespecially when it has Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,an inelastic demand. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Here's another application\Nof elasticity of demand Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and how it can be used\Nto understand our world. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,This is a quotation from 2012\Nfrom NPRs food blog "The Salt." Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,"You've all heard a lot Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,about this year's devastating\Ndrought in the Midwest, right? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,US Department of Agriculture\Nannounced last Friday Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,that the average US cornfield\Nthis year will yield less per acre Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,than it has since 1995. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Soybean yields are down, too. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So you think that farmers\Nwho grow these crops Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,must be really hurting. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And that's certainly the impression\Nyou get from media reports. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,But how's this,\Nfor a surprising fact? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,On average, corn growers\Nactually will rake in Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,a record amount of cash\Nfrom their harvest this year." Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So can you explain this secret side\Nof the drought? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,I'm not going to answer\Nthis question. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,This is exactly the type\Nof question you might receive Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,on an exam. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,But you should be able\Nto answer it by now, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,with a few sketches\Non a piece of paper. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And in particular, what I want you\Nto answer is, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,what type of demand curve,\Nfor corn, would make exactly Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,this type of outcome\Nperfectly understandable? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Not a secret or surprise,\Nbut perfectly understandable. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Okay, that's the elasticity\Nof demand. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Next time we'll be taking up\Nthe elasticity of supply, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and we'll be able to move\Nthrough that material much quicker Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,because it covers\Nmany similar concepts. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Thanks. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,- [Narrator] If you want\Nto test yourself, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,click Practice Questions,\Nor if you're ready to move on, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,just click Next Video. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,♪ [music] ♪