quantitative-methods/acjlecturesday2.org

#+TITLE: Quantitative Methods
#+PROPERTY: header-args:R :session acj :eval never-export
#+STARTUP: hideall inlineimages hideblocks
#+HTML_HEAD: <style>#content{max-width:1200px;} </style>

* Title slide                                                         :slide:
#+BEGIN_SRC emacs-lisp-slide
(org-show-animate '("Quantitative Methods, Part-II" "Vikas Rawal" "Prachi Bansal" "" "" ""))
#+END_SRC
* Day 2

** Paul Krugman on Fiscal Austerity                                  :slide:

#+attr_html: :width 1200px
[[file:krugman1.png]]
Source: [[https://www.nytimes.com/2018/11/02/opinion/the-perversion-of-fiscal-policy-slightly-wonkish.html]]


** Paul Krugman on Fiscal Austerity                                  :slide:

"Here’s what fiscal policy should do: it should support demand when the economy is weak, and it should pull that support back when the economy is strong. As John Maynard Keynes said, “The boom, not the slump, is the right time for austerity.” And up until 2010 the U.S. more or less followed that prescription. Since then, however, fiscal policy has become perverse: first austerity despite high unemployment, now expansion despite low unemployment.

** Unemployment and Fiscal Austerity                                 :slide:

#+name: fxed-krugman-graph
#+RESULTS: graph2
[[file:krugman2.png]]

#+NAME: graph2
#+BEGIN_SRC R :results output graphics :exports results :file krugman2.png :width 3774 :height 3774  :res 600
  library(data.table)
  library(ggplot2)
  fread("~/ssercloud/acj2018/krugmandata.csv")->a
  as.Date(a$date,format=c("%m/%d/%Y"))->a$date
  factor(ifelse(a$date<"10-01-01","2000-2009","2010-2018"))->a$Period
  melt(a,id=c("date","Period"),m=c("impact","unemployment"))->t
  levels(t$variable)<-c("Fiscal stimulus","Unemployment rate")
  ggplot(t,aes(x=date,y=value,group=variable,colour=Period))->p
  p+geom_line(size=1.2)+facet_wrap(~variable,scales="free_y",ncol=1)->p
  p+scale_y_continuous("Per cent")+theme(legend.position="bottom")
#+END_SRC


** Sampling Distributions                                            :slide:

#+RESULTS: sampling2
[[file:bsample2.png]]

#+NAME: sampling2
#+BEGIN_SRC R :results output graphics :exports results :file bsample2.png :width 4500 :height 3000  :res 600
    library(data.table)
    readRDS("plfsdata/plfsacjdata.rds")->worker
    worker$standardwage->worker$wage
    #read.table("~/ssercloud/acj2018/worker.csv",sep=",",header=T)->worker
    c(1:nrow(worker))->worker$SamplingFrameOrder
    worker[sex!=3,]->worker
    library(ggplot2)
      ggplot(worker,aes(wage))+geom_density(colour="black",size=1)+scale_y_continuous(limits=c(0,0.05))+scale_x_continuous(limits=c(0,600),breaks=c(0,mean(worker$wage),1000))->p
  #    p+facet_wrap(~sex)->p
      p+annotate("text",x=380,y=0.045,
               label=paste("Population mean = ",round(mean(worker$wage)),sep=""))->p
      p+annotate("text",x=400,y=0.042,
               label="Distribution of sample means:")->p
     p+theme_bw()->p
      p



    sample(1:nrow(worker),5, replace=FALSE)->a1
    worker[a1,]->s1
    mean(s1$wage)->t1
    for (i in c(1:9999)) {
        sample(1:nrow(worker),5, replace=FALSE)->a1
        worker[a1,]->s1
        c(t1,mean(s1$wage))->t1
    }

    data.frame(sno=c(1:10000),meancol=t1)->t1
    p+geom_density(data=t1,aes(meancol),colour="blue",size=1)-> p
    paste("Sample size 5: mean = ",
          round(mean(t1$meancol)),
          "; stdev = ",
          round(sqrt(var(t1$meancol))),sep="")->lab
    p+annotate("text",x=450,y=0.030,label=lab,colour="blue")->p
    p

    sample(1:nrow(worker),20, replace=FALSE)->a1
    worker[a1,]->s1
    mean(s1$wage)->t0
    for (i in c(1:9999)) {
        sample(1:nrow(worker),20, replace=FALSE)->a1
        worker[a1,]->s1
        c(t0,mean(s1$wage))->t0
    }

    data.frame(sno=c(1:10000),meancol=t0)->t0
    p+geom_density(data=t0,aes(meancol),colour="darkolivegreen",size=1)-> p
    paste("Sample size 20: mean = ",
          round(mean(t0$meancol)),
          "; stdev = ",
          round(sqrt(var(t0$meancol))),sep="")->lab
    p+annotate("text",x=450,y=0.033,label=lab,colour="darkolivegreen")->p
    p

    sample(1:nrow(worker),50, replace=FALSE)->a1
    worker[a1,]->s1
    mean(s1$wage)->t
    for (i in c(1:9999)) {
        sample(1:nrow(worker),50, replace=FALSE)->a1
        worker[a1,]->s1
        c(t,mean(s1$wage))->t
    }

    data.frame(sno=c(1:10000),meancol=t)->t
    p+geom_density(data=t,aes(meancol),colour="red",size=1)-> p
    paste("Sample size 50: mean = ",
          round(mean(t$meancol)),
          "; stdev = ",
          round(sqrt(var(t$meancol))),sep="")->lab
    p+annotate("text",x=450,y=0.036,label=lab,colour="red")->p
    p

    sample(1:nrow(worker),200, replace=FALSE)->a1
    worker[a1,]->s1
    mean(s1$wage)->t4
    for (i in c(1:9999)) {
      sample(1:nrow(worker),200, replace=FALSE)->a1
      worker[a1,]->s1
      c(t4,mean(s1$wage))->t4
    }

    data.frame(sno=c(1:10000),meancol=t4)->t4
    p+geom_density(data=t4,aes(meancol),colour="pink",size=1)-> p
    paste("Sample size 200: mean = ",
          round(mean(t4$meancol)),
          "; stdev = ",
          round(sqrt(var(t4$meancol))),sep="")->lab
    p+annotate("text",x=450,y=0.039,label=lab,colour="pink")->p
    p
#+end_src