2013年-世界发展银行全球_Decomposing_the_Labor_Market_Earnings_Inequality__The_Public_and_Private_Sectors_in_Vietnam_1993-2006_42页_496kb

报告摘要

Summary of "Decomposing the Labor Market Earnings Inequality: The Public and Private Sectors in Vietnam, 1993-2006"

Core Content

This working paper by Clément Imbert analyzes the evolution of labor market earnings inequality in Vietnam between 1993 and 2006, focusing on the public-private sector pay gap and its implications for overall inequality. The paper uses a comparative advantage model to disentangle the effects of worker sorting across sectors and differences in wage-setting policies on earnings inequality.

Main Views

Earnings Inequality Trends: Despite the overall decrease in wage inequality in Vietnam, the earnings gap in favor of public employees widened significantly over the period.
Public-Private Pay Gap: The pay gap between public and private sector workers increased from 1993 to 2006, with public sector workers earning more in 2006 compared to private sector workers.
Role of Sorting and Wage Policies: The widening of the public-private pay gap is primarily attributed to changes in compensation patterns, rather than just the sorting of workers based on their comparative advantage.
Comparative Advantage Model: The model introduces a latent variable of comparative advantage to capture unobserved worker characteristics that influence their sectoral allocation and earnings.

Key Information

Data Overview

The study uses Vietnam Living Standard Surveys (VLSS) for 1993 and 1998, and Vietnam Health and Living Standard Surveys (VHLSS) for 2002, 2004, and 2006.
The data is representative of Vietnam, with appropriate sample weights.
A panel design is used to track transitions between sectors, with the "2002-2006" panel created by combining 2002-2004 and 2004-2006 data.

Sectoral Employment Trends

In 1993, only 3.12% of rural workers and 20.01% of urban workers were employed in the public sector.
By 2006, these figures increased to 5.90% and 21.51%, respectively.
The proportion of private employees increased, but the public share of the labor market remained relatively stable at around one-third in rural areas and one-half in urban areas.

Earnings Differences

Nominal hourly earnings for public sector workers increased from 1,460 dongs in 1993 to 9,320 dongs in 2006, compared to 1,321 dongs to 5,747 dongs for private sector workers.
Hourly benefits also increased significantly, especially in the public sector.
Hours worked rose slightly more in the private sector, contributing to lower growth in hourly earnings compared to the public sector.

Earnings Distribution

The public sector wage distribution became more dominant in 2006 compared to 1993.
Within-sector inequality decreased over time, which explains the overall decline in wage inequality.
The public sector experienced a greater reduction in inequality than the private sector.

Empirical Strategy

The model is based on the Roy model, which assumes that workers differ in their productive characteristics and are sorted into sectors based on their comparative advantage.
The model includes:
- A latent variable of comparative advantage ($\theta_i$) that influences earnings differently in public and private sectors.
- A constant premium ($\eta_t$) for public sector employment.
- A sector-specific return to comparative advantage ($\alpha$) that affects both within- and between-sector inequality.
The model is just identified, with nine equations and nine parameters to estimate, including the average of $\theta_i$ across different employment history groups.

Identification and Estimation

The model uses employment history groups (e.g., stayers in public, switchers to public) to identify the effects of sorting and wage-setting.
The nonlinear least squares method is used for estimation.
The residual $\epsilon_{it}$ includes both idiosyncratic shocks ($u_{it}$) and individual-specific terms ($\zeta_i$), which are uncorrelated with employment history dummies.
The model allows for clustering of standard errors to account for serial correlation.

Interpretation of Results

The public-private pay gap widened due to changes in wage-setting policies, not just sorting.
In the 1990s, public sector workers were underpaid relative to their potential in the private sector.
By the 2000s, public sector workers were paid at least as well as private sector workers.
The increasing homogeneity in returns to skills in the Vietnamese labor market explains both the increase in the public-private pay gap and the decrease in overall inequality.

Conclusion

The paper highlights the importance of sectoral wage-setting in shaping earnings inequality.
It suggests that public sector reforms have had a mixed impact on inequality, with wage compression in the public sector contributing to lower within-sector inequality.
The evolution of the labor market during the transition period provides insights into how economic development in Vietnam will continue to affect households and society in the future.