Hello @Kathy291,
I see a discrepancy between them as well. In my case it's because the earnings summary accounts for the days in 2017 that guests stayed. If guests stayed on 200 days and the nightly rate was €20 the earnings summary would say €4,000.
However, the transaction history page shows only payouts made during 2017. That includes payouts for stays at the end of December 2016 which were paid to me in early January 2017. Also it does not include payouts for stays made at the end of December 2017 as these were made to me in early January 2018.
So, if you had a large payout in early January 2017 for a stay in December 2016 or a payout in early January 2018 for an end of December 2017 stay that might account for the discrepancy.
If that doesn't account for the difference and you have missing payouts you should contact Airbnb support.
Steve.