accuracies Arie ten Cate Estimating reporting accuracies exp imp - - PowerPoint PPT Presentation

The harmonisation of mirror data using simultaneously estimated accuracies

Arie ten Cate

Estimating reporting accuracies

• discrepancies Δ𝑗𝑘 ≡ 𝑦𝑗𝑘

exp − 𝑦𝑗𝑘 imp

• average discrepancy per country?
• simultaneously estimate all accuracies
• accurate: small bias or small variance?

The bias model

• every country has an export bias and an

import bias E Δ𝑗𝑘 = 𝜈𝑗

exp − 𝜈𝑘 imp

• Tsigas, Hertel & Binkley, 1992
• restriction needed

Σ μ𝑗

exp + Σ μ𝑘 imp = 0

The variance model

• every country has an export variance and an

import variance

• independent reporters

Var Δ𝑗𝑘 = 𝑊

𝑗 exp + V 𝑘 imp

• Stone, Champernowne and Meade, 1942
• restriction Σ 𝑊

𝑗 exp = Σ 𝑊 𝑘 imp

• hard to estimate
• multiple likelihood maxima

Applications

• Trade in services in the EU

– very large discrepancies – UK, Germany, France, Italy

• World trade in goods

– data Tsigas et al. – USA, Japan, EC, other W-Europe, NewZealand