[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,,- [Instructor] The path from cause \Nto effect is dark and dangerous.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,But the weapons \Nof Econometrics are strong.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,[Attack] with fierce \Nand flexible instrumental variables
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,when nature blesses you \Nwith fortuitous random assignment.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,[gong rings]
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Randomized trials are the surest \Npath to ceteris parabus comparisons.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Alas, this powerful tool \Nis often unavailable.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,But sometimes, randomization \Nhappens by accident.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,That's when we turn \Nto instrumental variables,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,IV for short.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,- [Voice whispers] Instrumental \Nvariables.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,- [Instructor] Today's lesson \Nis the first of two on IV.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Our first IV lesson begins \Nwith a story of schools.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,- [Josh] Charter schools \Nare public schools
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,freed from daily district oversight\Nand teacher union contracts.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,The question of whether charters \Nboost achievement
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,is one of the most important
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,in the history \Nof American education reform.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,- The most popular charter schools\Nhave more applicants
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,so the luck of the lottery draw \Ndecides who's offered a seat.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,A lot is at stake for the students \Nvying for their chance.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Waiting for the lottery results \Nbrings up lots of emotions
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,as was captured \Nin the award-winning documentary
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,"Waiting For Superman."
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,- [Mother] Don't cry.\NYou're gonna make Mommy cry.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Okay?
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,- Do charters really provide\Na better education?
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Critics most definitely say no,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,arguing that charters enroll \Nbetter students to begin with,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,smarter or more motivated\Nso differences in later outcomes
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,reflects selection bias.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,- [Kamal] Wait, this one seems easy.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,In a lottery, winners \Nare chosen randomly,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,so just compare winners and losers.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,- [Student] Obviously.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,- On the right track, Kamal,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,but charter lotteries \Ndon't force kids into
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,or out of a particular school.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,They randomize offers \Nof a charter seat.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Some kids get lucky.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Some kids don't.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,If we just wanted to know \Nthe effect of charter school offers,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,we could treat this \Nas a randomized trial.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,But we we're interested \Nin the effects
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,of charter school attendance,\Nnot offers.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And not everyone \Nwho is offered, accepts.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,IV turns the effect of being offered\Na charter seat into the effect
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,of actually attending \Na charter school.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,- [Student] Cool.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,- Oh nice.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,- Let's look at an example, \Na charter school from
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,the Knowledge Is Power \NProgram, or KIPP for short.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,This KIPP school is in Lynn,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,a faded industrial town \Non the coast of Massachusetts.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,The school has \Nmore applicants than seats
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and therefore picks its students\Nusing a lottery.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,From 2005 to 2008,\N371 fourth and fifth graders
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,put their names \Nin the KIPP/Lynn lottery,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,253 students won a seat at KIPP,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,118 students lost.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,A year later, lottery winners had \Nmuch higher match scores
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,than lottery losers.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,But remember, \Nwe're not trying to figure out
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,whether winning a lottery \Nmakes you better at math.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,We want to know if attending KIPP\Nmakes you better at math.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Of the 253 lottery winners,\Nonly 199 actually went to KIPP.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,The others chose \Na traditional public school.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Similarly of the 118 lottery losers,\Na few actually ended up at KIPP.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,They got an offer later.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So what was the effect of test scores\Nof actually attending KIPP?
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,- [Student] Why can't we just \Nmeasure their math scores?
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,- [Instructor] Great question.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Who would you compare them to?
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,- [Student] Those who didn't attend.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,- [Instructor] Is attendance random?
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,- [Camilla] No.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,- Selection bias.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,- [Instructor] Correct.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,- [Otto] What?
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,- [Instructor] The KIPP offers \Nare random so we can be confident
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,of ceteris parabus,\Nbut attendance is not random.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,The choice to accept the offer \Nmight be due to characteristics
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,that are