1. Do corporate taxes hinder innovation?
黎雨韵

2. Do Corporate Taxes Hinder Innovation?
Authors: Abhiroop Mukherjee,  Manpreet Singh,  Alminas Žaldokas
Publisher: Journal of Financial Economics,  Volume 124, Issue 1,  April 2017, Pages
Keywords: Innovation; Patents; Research and development; New products; Corporate taxes
Abstract: We exploit staggered changes in state-level corporate tax rates to show that an increase in taxes reduces future innovation. A variety of tests, including those based on policy discontinuity at contiguous counties straddling borders of politically similar states, show that local economic conditions do not drive our results. The effect we document is consistent across the innovation spectrum: taxes affect not only patenting and R&D investment but also new product introductions, which we measure using textual analysis. Our empirical results are consistent with models that highlight the role of higher corporate taxes in reducing innovator incentives and discouraging risk- taking.

3. 1. Introduction
Corporate tax systems are prominent in much of the political and economic discourse around the world today. Do corporate taxes have any real effect on the innovative competitiveness of economies?
This paper examines staggered corporate income tax changes at the US state level over 1990–2006, and find that higher corporate taxes indeed reduce future innovation by affected firms.
This paper provides first evidence that tax increases lead to a decrease in innovation across every step of innovation process—R&D, patents, and our newly developed measure of new products—and that the tax effect is neither driven by local economic changes nor by biases related to the predictability of tax changes.

4. 2. Data Patent data is from the National Bureau of Economic Research.
Due to constraints on the joint availability of tax, business address location, and patent data, this paper focuses in the period 1990–2006.
Patent data is from the National Bureau of Economic Research.
All financial variables of the firm and the state-level macroeconomic variables are from the Bureau of Labor Statistics.
Exclude firms in the financial sector and the public sector. Only look at firms headquartered in the US.
Final sample consists of 47,632 firm-year observations.

5. 3. Method of analysis and empirical results
Use a difference-in-differences approach to control for time-invariant, firm-specific omitted variables as well as time-varying industry trends and nationwide shocks.
How the corprate tax changes might affect innovation?
1. Patenning activity
2. R&D spending
3. New product announcements
4. Innovation quality

6. 3. Method of analysis and empirical results
3.1 Patenning activity
Variables
meanings
Ln(1 + #Patents)i,s,t+k
Natural logarithm of total number of patents applied for by firm i in financial year t
Tax decreasest
Dummy variable equal to one in the year of corporate tax deduction for the firms headquartered in state s, else zero
Tax increasest
Dummy variable equal to one in the year of corporate tax increase for the firms headquartered in state s, else zero
Xit
Firm-level factors that can affect innovation.
Xit includes the logarithm of firm sales and capital-labor ratio, change in profitability, asset tangibility, presence of a debt rating on the firm, R&D-to-sales ratio, HHI and its square term, change in state’s GSP, change in total tax revenues of the state as a proportion of GSP, change in the state’s population (in logs), and change in the state’s unemployment rate.

7. 3. Method of analysis and empirical results
3.1 Patenning activity
Columns 1–3 report results with county-pair-year fixed effects and county-pair-year as well as industry-year fixed effects in columns 4–6.
We find that the average treated firm files one fewer patent following a tax increase, as compared to an aver- age control firm. However, we do not find any systematic effect following tax cuts.

8. 3. Method of analysis and empirical results
3.1 Patenning activity
In addition, this paper address the two main concerns with any analysis that tries to identify the effect of legal changes such as changes in taxes: (1) some of the tax changes might have been predicted and so firms could have adjusted in advance, in which case our estimates could be biased; (2) spurious correlation as tax changes could be driven by economic conditions that at the same time affect firm innovation directly.
Find consistent results: fail to uncover any significant effects from tax cuts but tax increases continue to remain significant in the data

9. 3. Method of analysis and empirical results
3.2 R&D spending
Variables
meanings
R&D/Sales
Ratio of expense on research and development to sales
Ln(1+R&D)
Natural logarithm of research and development
Tax decreasest
Dummy variable equal to one in the year of corporate tax deduction for the firms headquartered in state s, else zero
Tax increasest
Dummy variable equal to one in the year of corporate tax increase for the firms headquartered in state s, else zero
Xit
Firm-level factors that can affect innovation.
Xit includes the logarithm of firm sales and capital-labor ratio, change in profitability, asset tangibility, presence of a debt rating on the firm, R&D-to-sales ratio, HHI and its square term, change in state’s GSP, change in total tax revenues of the state as a proportion of GSP, change in the state’s population (in logs), and change in the state’s unemployment rate.

10. 3. Method of analysis and empirical results
3.2 R&D spending
In terms of economic magnitudes, our most conservative measure (column 1) shows that R&D to sales declines by 4.3% of its sample mean after a tax increase.
In addition, authors repeat tests but again focus on unpredictable tax changes and contiguous-county- level neighboring firms straddling policy-wise similar state borders.
Find that R&D also declines following tax in- creases, and local economic effects or predictability-driven biases are unlikely to be driving these results.

11. 3. Method of analysis and empirical results
3.3 New product announcements
Major new product launches are affected by tax changes. In constructing measures of new product announcements, this paper combines textual analysis with event studies conducted on stock market returns. look at a firm’s stock price reaction to measure the expected value of the product announcement.
Variables
meanings
Sum of all positive CARs
Sum all positive cumulative abnormal returns over the year
Major new products
Count the number of announcements with the cumulative abnormal returns above the 75 percentile year by year after adjusting for firm size and book-to-market ratio
Tax decreasest
Dummy variable equal to one in the year of corporate tax deduction for the firms headquartered in state s, else zero
Tax increasest
Dummy variable equal to one in the year of corporate tax increase for the firms headquartered in state s, else zero
Xit
firm-level factors that can affect innovation.

12. 3. Method of analysis and empirical results
3.3 New product announcements
In terms of economic magnitudes, the number of major new product introductions by firms drops by 5.1% in the first year after a tax rise.
In addition, authors repeat tests but again focus on unpredictable tax changes and contiguous-county- level neighboring firms straddling policy-wise similar state borders. Observe similar results as in the panel A.

13. 3. Method of analysis and empirical results
3.4 Innovation quality
Measure innovation quality by weighting each patent using the number of future citations that it received from subsequent patents. In addition to capturing economic value, forward citations also reflect the technological importance of patents as perceived by the inventors and experts.
Variables
meanings
Citations
Total citations received on patents applied for adjusted for truncation
Citations /Patenes
Ratio of total citations received on patents applied for adjusted for truncation and total number of patents applied for by firm i in financial year t
Tax decreasest
Dummy variable equal to one in the year of corporate tax deduction for the firms headquartered in state s, else zero
Tax increasest
Dummy variable equal to one in the year of corporate tax increase for the firms headquartered in state s, else zero
Xit
firm-level factors that can affect innovation.

14. 3. Method of analysis and empirical results
3.4 Innovation quality
Results show that the quality of innovation also declines following tax increases. This mirrors our earlier evidence on the number of patents.
Repeat tests but again focus on unpredictable tax changes and contiguous-county- level neighboring firms straddling policy-wise similar state borders, and show that our results remain similar.

15. 4. Heterogeneity of the effect
4.1 Marginal tax rates Firms differ in terms of their exposure to tax changes depending on their (past and current) earnings. Authors measure a firm’s exposure to tax changes using the marginal tax, measured in the year of the tax change. Do not see any change in their innovation outputs in the predicted direction following the tax change. Firms with high marginal tax rates indeed file a lower number of patents in response to tax increases. 4.2 Tax sheltering Firms also differ in their ability to shelter taxes. This pattern is consistent with a view that firms in states that do not require combined reporting shift out patenting activity after experiencing a tax increase in their home state, but this shift takes time.

16. 4. Heterogeneity of the effect
4.3 Location of operations and apportionment rules The geographic distribution of firm operations across different states in terms of employees, sales, and assets In terms of economic magnitudes, our evidence shows that a treated firm, with 100% instate exposure, files for one fewer patent in the 2 years following an increase in taxes in its state. Again, do not find any significant effect following tax cuts.

17. 5. Robustness
Overall, find that basic result on tax increases is robust. In some specifications tax cuts also have an effect, but this effect is smaller when present, and not robust.

18. 6. Conclusion
Find evidence that firms respond to tax increases by filing a lower number of patents, investing less in R&D, and bringing fewer new products into the market, which, taken together, suggests that higher corporate taxes indeed reduce innovator incentives and discourage risk-taking.
Find weaker results on increasing innovation in response to tax cuts.

19. 7. Comment
This paper focus on the full innovation process. Patents are intermediate product in the innovation. R&D spending is the input of innovation. New products are the output of innovation. We can find how tax changes effect every innovation process.
This paper contributes to the research on factors of affecting the innovation. It is believed that the company's tax is the primary determinant of the company's innovation.
There is a shortcoming when authors construct measures of new product announcements, which is that if the stock market anticipates new products even before the company first discusses them in a newsworthy fashion, then the market-return screen employed here will be noisy.

20. THE END