Table 1.
Summary statistics of worker effort, heat exposure and worker demographic characteristics for 575 workers.
Table 2.
Task descriptions and number of workers by pay arrangement.
Table 3.
The distribution of workers across tasks monthly.
Table 4.
Shift starting and ending hours for workers paid by piece rate and hourly rate.
Table 5.
The impact of piece-rate arrangements and heat exposure (measured in WBGT) on workers’ effort (units in 0.01 Metabolic Equivalents, METs) based on regression results using a full sample.
Fig 1.
Marginal response in effort with respect to WBGT for workers paid by different pay arrangements based on regression coefficients from Table 5 Column 3.
Note: The solid gray line shows the marginal change in workers’ effort for whom is paid by hourly wages when there is one degree increase in heat exposure. The dotted yellow line shows the marginal change in workers’ effort for whom is paid by piece rates when there is one degree increase in heat exposure. The gray bound around each line shows he 95% confidence intervals.
Fig 2.
Differences in effort between workers paid by piece-rate arrangements and hourly wages in response to WBGT based on regression coefficients from Table 5 Column 3.
Note: The solid line curve shows the differences in worker effort between workers paid by different schemes. The gray area shows the 95% confidence interval of the metabolic differences. The dot-dashed lines show the cut-off points of hourly WBGT where the estimated 95% confidence interval of the differences in metabolic rates between workers paid by piece rate and hourly rate is above zero. The dashed lines show the cut-off points of hourly WBGT where the estimated 95% confidence interval of the differences in metabolic rates between workers paid by piece rate and hourly rate is below zero.
Table 6.
The impact of piece rate and heat exposure (measured in WBGT) on workers’ effort (units in 0.01 METs) based on regression results using a matched sample (Values in parentheses are standard errors).
Fig 3.
Marginal response in effort with respect to WBGT for workers paid by different pay arrangements based on regression coefficients from Table 6 Column 3.
Note: The solid gray line shows the marginal change in workers’ effort for whom is paid by hourly wages when there is one degree increase in heat exposure. The dotted line shows the marginal change in workers’ effort for whom is paid by piece rates when there is one degree increase in heat exposure. The gray bound around each line shows the 95% confidence intervals.
Fig 4.
Differences in effort between workers paid by piece rate and hourly wage rate in response to WBGT based on regression coefficients from Table 6.
Note: The dot-dashed lines are the cut-off points of hourly WBGT where the estimated 95% confidence interval of the differences in metabolic rates between workers paid by piece rate and hourly rate is above zero. The dashed lines are the cut-off points of hourly WBGT where the estimated 95% confidence interval of the differences in metabolic rates between workers paid by piece rate and hourly rate is below zero.