## Linking Workshop Exercise 3
library(ipumsr)
library(dplyr)
library(tidyr)
library(tidyverse)

ddi <- read_ipums_ddi("cps_00052.xml")
data <- read_ipums_micro(ddi)

# Check for duplicate persons (based on CPSIDP)
count_duplicates <- data %>%
  group_by(CPSIDP) %>%
  summarize(n = n())

# MISH values for December records that link
# First Link the datasets to identify MISH for each in a linked dataset
dec_2014 <- data %>%
  filter(YEAR==2014 & MONTH==12) %>%
  select(CPSIDP, AGE, SEX, RACE, MISH)
# December 2014 dataset
asec_2015 <- data %>%
  filter(YEAR==2015 & MONTH==3 & ASECFLAG==1) %>%
  select(CPSIDP, AGE, SEX, RACE, MISH)
# Merge data frames
linked_df <- merge(dec_2014, asec_2015, by = "CPSIDP")