Chinese Political History II: Chapter 5, Exercise 1 — Possible Solution
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TASK
Two sources give different extreme-poverty figures. Explain why they cannot
be combined into one series and what conclusion is still safe.

ANSWER

THE FIGURES
  Source A: 88.1 percent (1981) to 0.2 percent (2019)
  Source B: 67 percent (1990) to under 1 percent (2015)

WHY NOT COMBINE
- The start and end years differ (1981-2019 against 1990-2015).
- The chapter's sources do not say which poverty line each uses, so the
  levels are not comparable: the 1990 value is 67 percent in one and would
  be somewhere between 88.1 and 0.2 in the other, but I cannot say where.
- Splicing two series with different definitions would produce a false
  trend.

SAFE CONCLUSION
Both show extreme poverty falling from a majority of the population to
under one percent. Say that, and give each figure with its source and
years.

CAUTION
The "about 800 million lifted out, 1978-2018" figure is single-source and
uses a third window, so quote it as reported.