I encourage you to read his old article https://ourworldindata.org/extreme-poverty-in-brief https://ourworldindata.org/extreme-poverty-in-brief in which he talk

I encourage you to read his old article https://ourworldindata.org/extreme-poverty-in-brief https://ourworldindata.org/extreme-poverty-in-brief in which he talks about the cutout and what he did to minimize the effect. (He adjusts per purchasing power through time and location)