Consider a simple model to explain a city's automobiles accidents (totacc) in terms of number of cars in the city (totcar):

log(totacc_t) = 0 + 1 log(totcar_t) + u_t (1)

Estimating (1) using annual data from 1949-2020 gives

log(totacct) = 24.56 (3.21) + 0.88 (0.30) log(totcar_t), (2) n = 72, R2 = .473,

Consider a simple extension of model (1):

log(totacc_t) = 0 + 1 log(totcar_t) + 2 log(totcar_t1) + u_t

After a 1% permanent increase in log(totcar_t),

(i) How much log(totacc_t) changes on impact?

(ii) How much log(totacc_t) changes after one period?

(iii) How much log(totacct_t) changes after two periods?