Hello,
I need to run some regressions in Stata with a few conditions. I am examining data on incentive contracts in baseball and their impact on player performance. I want to run a regression to determine: (a) whether a player having incentives in their contract is impacted by a few variables, such as player position, age, whether they've had a major injury, and variance in the years before signing a contract (b) if certain player statistics were impacted by having incentives in their contract, and (c) whether player earnings increased by having incentives in their contract. A basic example of how my data is structured is below:
Player Position Age Major Injury Offseason Year Contract Signed Contract Years Contract Amount Incentives in Contract 2015 Incentives in Contract 2016 Incentives in Contract 2017 Incentives in Contract 2018 Incentives in Contract 2019
Max Scherzer 1 30 0 2015 7 210000000 1 1 1 1 1


Player Year Games Started ERA WAR
Max Scherzer 2012 33 3.74 4.4
Max Scherzer 2013 32 2.90 6.5
Max Scherzer 2014 33 3.15 5.8
Max Scherzer 2015 33 2.79 6.9
Max Scherzer 2016 34 2.96 6.2
Max Scherzer 2017 31 2.51 7.2
Max Scherzer 2018 33 2.53 8.4
Max Scherzer 2019 27 2.92 5.5

So in the first regression, I want to basically examine some of the columns in the first table along with some data in the second table before the contract was signed. In the second regression, I want to examine the statistics after the contract was signed. Does anyone have any idea how to add in these conditions? I think I have sufficiently merged the data.