I'm studying the employment tenure (the duration of contracts) and the temporary employment rate of certain social groups before and after labour market reforms. So far I've performed descriptive analyses, but I would like to consider doing some multivariate analyses of the variables so I can do some causal inference beyond "looks like employment tenure has gone down for female workers, perhaps they were affected by the reform".

My question is, what sort of multivariate analyses can be performed with a continuous variable such as employment tenure and with the temporary employment rate? If I understand it right, the independent variable would be the year "after the reform" (as the event), but how can I measure the (purported) effect on employment tenure or the temporary employment rate?
Thanks a lot!