5 ms·
I believe the paper discussed is here [0]. I've skimmed it and am somewhat underwhelmed by both the methods and theory: * All of their regressions are in level
by webel0 6y ago
I believe the paper discussed is here [0]. I've skimmed it and am somewhat underwhelmed by both the methods and theory:
* All of their regressions are in levels.
* Look at Table 1, Column 1.
* Robotics investment is positively correlated with overall employment.
* What this tells me is that, "Large companies, by dint of their being large, make large investments. Some of those investments are in robotics. Likewise for small companies."
* To me, it has nothing to do with the claim "More robots => more employment."
* Running regressions in first differences would be better (but not enough).
* Then you could begin to work towards an interpretation like, "companies that _increased_ their investment in robotics in year X tended to increase/decrease employment/management/turnover by X." You can account for lags and the like via your specification.
* Fixed effects _are not_ equivelant to first differences in this setup!
* Separate out the long-, medium- and short-term consequences:
* Investment in new technology may require hiring new "talent" that is knowledgeable of the tech.
* In cases where there is a tech shock and firms are all buying the same machine, demand for a certain skillset will grow quickly. So you'd likely see:
* An uptick in turnover among affected workers
* A move to a "flatter" organizational structure (various reasons). So maybe fewer people who are managers per se.
* Possibly short-term productvity decreases arising from implementation issues. (e.g. have to hire people to check the work of machine in staging manually while still running previous process.)
* Over time, though:
* Implementation issues/bugs are smoothed out
* Rare skills are commidified. The need to hire "superstars" ends.
* It is important to ask, "what might have caused investment by a given firm over a given time frame?"
* Common industry technological shocks might spur investment.
* (And the simplest way to account for technological shocks in this sort of regression you'd want `[industry] x [year]` fixed effects.)
* "We went on a manager hiring spree in year 1. Those managers, in turn, bought a lot of robots in year 2. In year 2 we hired fewer managers because we'd just hired a bunch in year 1."
* Reverse causation issues are pervasive.
* Finally, I think it is important to notice their notion of "robot adoption":
* They are talking about physical hardware _only_.
* Their measure of investment is coming only from import data. The set of firms that are going to go through the rigammarole of importing physical hardware is probably raher special: Probably:
* Larger
* Have a high expected ROI from investment
At the very least, this paper needs first-difference regressions and a good instrument that can help to disentangle what might be going on. For the instrument, it might make sense to look into changes in tariff duties over time [1].
---
[0] https://content.tcmediasaffaires.com/LAF/lacom2019/robots.pdf https://content.tcmediasaffaires.com/LAF/lacom2019/robots.pd...
[1] https://cbsa-asfc.gc.ca/trade-commerce/tariff-tarif/2020/html/tblmod-2-eng.html https://cbsa-asfc.gc.ca/trade-commerce/tariff-tarif/2020/htm...