1A.Definelabor productivity.How do we measure an individual worker's labor productivity?

1 B.Why is it difficult to measure the labor productivity of a government employee, even when an essential public service (e.g. police department, fire department, court house) is being performed?

1 C.Tim Harford says that labor productivity is greater in cities than in rural areas.He goes on to say that then internet has given cities evenmoreof a labor productivity advantage over rural cities.Explain Tim Harford's reasons.