There was also estimates for earlier years than 2030 but I don't have the time to dig them up right now and they are also net negative. They don't have all their payment reimbursed because they pay carbon tax on all their purchases indirectly via buying goods whose price has inflated due to carbon tax on transport, inputs, etc.
But to clarify the report's indirect costs is not due to (just) indirect costs on buying goods transported by carbon tax, but the report's additional "economic factors" is due to "the loss in employment and investment income".
But I personally find this take in their report unfair because the the alternative of not having the carbon tax isn't really the status quo, because there is an "economic cost" from climate change such as 'the interior of BC being hotter than death valley' and 'the town of Jasper burning down'.
That said, I do see that I'm rationalizing my personal beliefs on this topic, and that is also unfair.
Further, the major problem with a carbon tax in Canada that nobody is talking about is that the carbon tax has to be huge to cause change because Canada as regulated away all the substitution options so people only change their carbon output when they are made much poorer. In economics this is called inelastic demand. There are a massive number of changes to existing regulation that would increase substitution possibilities and make demand for carbon more elastic, making a lower carbon tax have a larger effect and making these changes harms noone and makes everyone materially better off because they have more options but we are instead choosing to try and have a large carbon tax because the regulatory changes are hard and across multiple levels of government. Here's a non exclusive list of things we could change to make a massive shift in carbon demand over time:
1. Relax zoning to allow more dwellings, more lot coverage, taller structures and more freedom for land owners across most of the cities including removing exclusions for single family only zoning (basically give people the ability to build single family if they want and also build a lot of other options.
2. Increase dedicated bike lane and walking infrastructure so that more people take those much cheaper to provide options that are drastically lower in carbon output.
3. In areas that densify enough to justify it, run more public transit, more frequently to make transit a viable option.
4. Deal with fire in six story and under building in a way that doesn't require a second internal fire escape staircase (this ruins floor plans making it way harder to do family friendly 3 bedroom units).
5. Remove or drastically decrease most minimum setback, parking space, contextual anything limitations and streamline building and development permits to make it easier to get this stuff building even though it is unpopular among a vocal minority of the population that tries to hold it up in committee.
*edit sorry first post was so long ago I forgot I touched on some of this already. I'm leaving it because the above is more detailed*
Your best bet is what I outlined (and it's not exclusive you can try and incentivize scrubbing at the same time) because demand for transport and residential doesn't easily move as longa s the people are there, so if you manage to shift say, 15-20% of transport to biking and walking and give people denser options that maintains usable square footage (i.e. not 400 square foot concrete shit boxes in the sky) and another 10-20% to much more efficient public transit, all of a sudden you've had a massive impact and made people super sensitive to carbon prices because they have viable alternatives to the 30 km a day suburbia car commute to the 2500 square foot single family detached house exposted on all sides to the weather. Instead they can, for example get a 2200 square foot 3 story row house only exposed on the roof and narrow front/back, or similar in a 3 story condo complex with one fire exit internal and one elevator allowing enough square footage to make something similar to the row house something that gets built.