• Labour redundancies exist
• Age-selective mismatches appear to occur.
• Human resource abundance can be etimated as the potential number of eligible labour force.

• Whether do "labour shortages" exist?
• Whether does age structure of labour force matter?
• How do we estimate abundance of human resource (HRA)?

• Level (\(\mu_{i}\)): Stable component over time
  • Phisycal performance
• Trend (\(\nu_{it}\)): Componet affected both age and chronological fluctuations
  • Demographic transition
• Intrinsic growth (\(\gamma_{t}\)): Component moving over time and independent of age class
  • Socioeconomic events

\[ Y_{it} \sim N(h_{it}, \sigma^{2}_{yi}) \\ h_{it} = \phi_{it} + \mu_{i} \\ \phi_{it} \sim N(\phi^{mean}_{it}, \sigma^{2}_{\phi_{i}}) \\ \phi^{mean}_{it} = \nu_{it} + \gamma_{t} \\ \nu_{it} \sim N(2\nu_{it-1} + \nu_{it-2}, \sigma^{2}_{\nu_{i}}) \\ \gamma_{t} \sim N(2\gamma_{t-1} + \gamma_{t-2}, \sigma^{2}_{\gamma_{t}}) \\ \]

Where:

\(Y_{it}\):Current labour force; \(h_{it}\):Estimated HRA; \(\phi_{it}\):Chronological fluctuation; \(\mu_{i}\):Level; \(\nu_{it}\):Trend; \(\gamma_{i}\):Intrinsic growth; \(\sigma^{2}_{yi}\), \(\sigma^{2}_{\phi_{i}}\), \(\sigma^{2}_{\nu_{i}}\), \(\sigma^{2}_{\gamma_{t}}\), :variance of each values

• Thailand has not appeared to experience \(Y_{it} > h_{it}\) (labour shortages).
• Rather, labour redundancy by age-selective mismatches
• In the future, the shortage may occur.