So my question is in regards to tax and tax policy, in our problem we work for the government and are asked to provide a policy recommendation regarding a tax change that we are currently considering: it is regards to introducing a tax on air travel arriving at provincial airports and/or introducing a toll on provincial highways. We can implement both at the same time or just one.

1. For the first part we are only interested in maximizing efficiency. So we're looking for which policy recommendation we should offer in this case and why we're recommending? Should we introduce only one tax or should the government split the tax burden between the two taxes? If so, should the tax burden be split equally across the two taxes?
2. Secondly, suppose the govt is now interested in equity as well as efficiency. does this change our policy recommendation? Why or why not?

We are given the following info on price elasticity of demand:

According to a study commissioned by the govt: a 10% increase in highway toll leads to a decrease of 2.1-2.7% (Price elasticity = -0.21 to -0.27). another report says price elasticity of demand for air travel is -0.80.