Week 12: Firm and Administrative Data

Administrative Data

Records generated as a by-product of running a programmable or rule; coverage and variables are set by that rule

NT-SARS tax data

Corportate income Tax returns (IT14, ITR14), employee payroll certificates (IRP5) customs, VAT201, individual returns (ITR12) accessed at the National Treasury Secure Data Facility

Matched employer-employee data

Records linking workers to the firms they work for over time

Worker premium

The wage component that follows a worker from firm to firm

Firm premium

The wage a firm pays above others for the same worker

AKM decomposition

Split wages into worker and firm effects using workers who move between firms

Perfect competition (labour)

Wage = marginal revenue product of labour (MRPL)

Monopsony

Employer market power: wage < MRPL, so the firm you work for matters

Coverage limitation

Tax data misses informal firms, the informally employed, the unemlpoyed and the non-employed

Unit of Analysis problem

A firm is the CIT or PAYE entity, which may be part of a group or sit at a head office, causing spurious entry and exit

Employment definition (admin)

Built from IRP5 declaration types by the researcher

• start and end dates are poorly recorded

Admin vs Survey Data

Admin data complements, but cannot replace, surveys and the census